Here I will try to explain how to change your pickups. It is a hard subject to show in a format
like this because there are an infinite number of ways to do it.
So I will walk you through the steps of doing standard wiring on a guitar with a DiMarzio five-way EP1104 Strat switch. The guitar has humbuckers in the bridge and neck position and a single coil in the middle.

The wiring I will use here will give us the following sounds:

1. Neck humbucker in series for max power.
2. Neck humbucker split together with middle single coil.
3. Middle single coil alone.
4. Bridge humbucker split together with the middle single coil.
5. Bridge humbucker in series for max power.

This setup uses a reverse magnetic polarity single-coil, which gives you pretty good hum canceling in positions 2 and 4. If you are using a standard polarity pickup in the middle, you must reverse its black and white wires to keep the pickup in phase with the humbuckers, and it will not be hum canceling in positions 2 or 4. With either polarity of middle pickup, positions 1 and 5 are always hum canceling, and position 3 is not hum canceling.

There are loads of variations on this that we could do, combinations with push/pull pots and mini switches or just hooking up the humbucker in parallel for example.
I think this is a good way to wire up an H-S-H guitar, to get the most useful sound combinations from it.
Most parts of the job will be the same no matter what sort of wiring you want to do. You just solder the wires differently.
You can find different wiring diagrams on DiMarzio.com.
You can also find wiring diagrams for all Ibanez models here.

Changing pickups is a fast and easy job.
This whole process took about 30 minutes (excluding the time to take all the photos).
The guitar I will work with has had its pickups changed many times so it will look a little messy on the pots and the switch. I’m not going to spend too much time on making the wiring and soldering look super nice but I’ll just concentrate on making it work well.
You can spend a little more time on every step and make it look really clean and nice if you want to.

I strongly recommend that you use the right tools for the job.
You should use a 25 to 40 watt soldering iron, but a 25 watt iron is best. Use only electronic grade rosin core solder, never acid core solder or acid flux.
You can easily destroy your switches and pots by using a high power soldering iron or gun, which makes the parts too hot. You can even cause damage with a 25 watt iron if you keep the connections hot for too long.
Before you touch the soldering iron to the work, clean the soldering tip on a wet piece of cloth or sponge and melt a very short length of solder (5 mm or less) onto the tip. The fresh solder will help carry the heat from the solder tip into the work quickly. Add a little more solder to the connection if necessary to make a good, smooth joint, and then remove the solder tip from the work and let the melted solder freeze without disturbing it.
If your solder joints look bumpy, wrinkled or dull, or if you move the wires while the solder is going from liquid to solid, this can cause problems down the road with buzzes, crackling noises or intermittent failure. If you make a bad joint, wait for it to cool down, then re-heat it with a little new solder until it's smooth and shiny.

I also really recommend that you try to go through all the different sounds that you can get from a humbucker pickup, series, parallel and split, just to get an idea of what they sound like, so you can find the ones you like the best. This will make it much easier to decide which wiring diagram you should use.

So, lets put a great Allan CD in the stereo and lets go to work.

1.
Here is the guitar that I will change pickups in. It’s an Ibanez RG1550.
I'm happy with the sound of the middle and neck pickups, so I will only change the bridge one. But I will re-wire the whole guitar and cut all the cables down so they won’t be longer then they need to be, to make it look less like a bird’s nest inside the guitar. Keeping the wires short also helps to reduce noise.
I will also flip the neck pickup around 180 degrees to get the coils I want in the right place when the pickup is split.
See more about that in sections 18 and 28.

I do the wiring a little differently if I know that the pickups will stay in the guitar or if I'm just trying something new. I have already tried out what pickups this guitar sounds the best with, so the wiring I will do now is permanent. These pickups will stay here forever.
I will have a DiMarzio PAF Joe in the neck, DiMarzio FS-1 in the middle and a DiMarzio Air Zone in the bridge. The switch inside the guitar is a DiMarzio five-way Strat switch (EP1104) and the pots are DiMarzio 500k custom taper potentiometers (EP1201).

The switch in your guitar might look different and might have to be hooked up differently, so if you feel unsure how your switch is wired, you could get the same as mine and hook it up the same way I do or you could figure out your switch based on the way it is hooked up when you open the guitar.

2.
This guitar has a pick guard so I need to remove the strings before I can do any work inside the guitar. See the guide for how to remove your tremolo without cutting your strings off.
If you have a guitar without pick guard, then you get to the inside of the guitar by removing the plastic cover plate on the back of the guitar, but you still need to get the strings off to be able to change the pickups.

3.
After you have the strings removed and out of the way, unscrew all the screws holding the pick guard in place. There are 10 screws on all Ibanez RG shape guitars, but it will be the same procedure on any guitar. An electric screwdriver makes the job so much faster (am I lazy or just modern?).

4.
Then you just lift the pick guard up from the guitar, but take it easy so you don't pull any wires off or you won’t know where they should go.
I want to get the whole pick guard away from the guitar so I wont scratch it.

5.
Turn the pick guard upside down, like this, so you can see where all the wires go.
You can put a piece of fabric under the pick guard so you won’t scratch the guitar.
Now take a paper and a pen and draw a picture of where all the little wires go, and you could also download and print out a wiring diagram from DiMarzio’s website.

There is no way that you can remember how it's all hooked up, so make sure to draw a diagram before you go any further. It won’t have to be anything fancy looking, just make sure that you understand it yourself. You can also turn it into a modern art masterpiece and put it on the wall.

6.
The next step is to remove the pick guard from the guitar because it makes it so much easier to work with and you won’t scratch the guitar. So we need to remove the ground (earth) wires (green arrows) and the output jack wires (blue arrows).

7.
Here is another angle to show you the wires I mean.

8.
Grab the wires with one hand and the cool end of the soldering iron with the other and heat up the solder until the wire comes free. Don’t pull it out, just let it slide off when it is warm enough.
Always make sure that no wires come in contact with the soldering iron or it might make the plastic insulation melt.

Make sure that you read the part about using the right tools at the start of this guide before you start soldering in your guitar.

9.
Here is an angle showing where the input wire goes on the volume pot.
White wire goes to “out” from the volume pot and silver goes to ground (earth).

10.
Remove them the same way you did with the ground (earth) wires. Try to heat things up quickly, but cook the parts as little as possible, just enough so the solder melts and lets go of the wires.

11.
Now we can remove the pick guard from the guitar.
You can see in this picture that it sort of looks like a bird’s nest inside this guitar. All the cables are way too long.
So I will change the bridge pickup and cut all the other cables so I can remove the excess wire.
Again, if you’re not sure that the pickups will stay in the guitar then don’t cut the cables short.
It will only make it hard to fit into another guitar if you make the cables too short.

12.
The first thing I do is remove the bridge pickup. So start by removing all the wires from the pickup with the soldering iron. It should be easy to follow what cables they are.

I also want to clean up the inside of this guitar, so I will remove all the wires from all the other pickups too. But if you only want to change one pickup and leave the others as they are, just jump down to step 18.

13.
Then we take the pickup away from the pick guard. So we can install the new one.
You do that by unscrewing the two pickup height adjustments screws that are holding the pickup in place (blue arrows).

14.
This is the way it will look with all the pickup wires removed.
I have left all the wires that are hooked up to the switch, the volume and tone knob as they are.
But you can remove and redo them to if you want to make it look super fancy.

15.
Now we have the old pickup loose and the new one in the box.
Take the new one out and put the old one in the box so it won’t be destroyed.
You will need the old pickup’s springs, so don’t put them in the box.
This is a very hard step so make sure that you know what you’re doing.

16.
Here is what you find in the pickup box.
Hopefully the pickup, height adjustment screws, a pickup instruction and a warranty card (I think this goes for all brands of pickups, if not, then shame on them).
Read through the pickup instruction to get an idea of how your pickup can be wired.

17.
Now let’s put the new pickup onto the pick guard. Just hold it the way I do in the picture and push the spring up on the screw (in the direction of the arrow) with the pickup. Then try to get the screw to grip in the pickup’s screw hole (No, you naughty man. Not there!). This can be a little annoying until you figure out how to do it.
It can end with you running around the room, trying to find the little spring after it takes off on you.

18.
Before we cut the cables to their right length, make sure to strap (or tape) them together like I have done on the picture. This will save your nerves when you try to put the pick guard back on the guitar again. Look at the picture below to see what I mean. The wires are supposed to follow the channels in the body so it really helps to have them strapped in the right place.

But wait, before you strap it up. In this picture, the neck pickup has to be turned around (180 degrees) in order for it to use the coil closest to the middle pickup when we split the neck pickup together with the middle pickup. Just loosen the screws and flip the pickup around (so the cable that comes out from the pickup comes from the other side of the pick guard, like the green line shows) and put it back on again.
See section 28 for more about this.

19.
Here you can clearly see where the cables should go. And that’s why we want to strap them up; it will make getting it all back together a whole lot easier.

20.
Now it's time to cut the wires to the right length.
Again, if you’re not sure that the pickups you are installing are the ones you will keep there, then don't cut the wires too short. Leave them long so you can install the pickup somewhere else when you take it out. It is very annoying to have pickups with wires too short.

But I'm sure that these pickups will stay here, so I make the wires just long enough to go where I want them to and there are two ways you can do this.

Make them just long enough that they will reach everywhere you want them inside the guitar. Then strip a little more of the plastic jacket on the cable so it can reach both to the switch and the volume pot.

21.
The second way is to cut them so they just reach to the volume pot and then extend the wires that go to the switch. That is what I will do in this guitar.

22.
Before we start to open the cables to get to the wires, let me just show what the cable is and what you will find in there. So here is a photo of a pickup cable.

First you have the plastic jacket around everything (blue arrow).
Under that is a thin metal film (red arrow) that works as a shield from outside noise interference.
Under that are the silver ground wire (yellow arrow) and a plastic film (green arrow) around the rest of the wires.
And finally, you have the actual lead wires (brown arrow) inside the plastic on each wire.

You can read more about the different wires in the pickup instruction paper. It will tell you what they are and what they do and how you can achieve more sounds from wiring them in different ways.

23.
Use a small, sharp knife to open the plastic jacket on the cable.
Be careful so you don’t cut too deep and into the wires underneath. You can feel the resistance from the shield layer, so don't cut through that.

24.
Just make a small cut like this. Just so you can open the plastic a little bit.
I have opened the shield layer too in this picture, it makes is a little easier to remove.

25.
Then you just pull the jacket off like this. I don't have to strip it very far for the way I will do the wiring in this guitar.

26.
I just stripped the jacket for 2.5 cm from the end.
Remove the shield layer and the thin plastic film too like I have done in the picture.

27.
This is the wiring diagram we will follow when we start to hook things up.
Take a look at it so you get a picture in your head of where the wires should go.

If you are having problems with reading the wiring diagram, then here is how it should be wired up.
Red from bridge pickup to switch point 1.
Black from middle pickup to switch point 2.
Red from neck pickup to switch point 3.
Black & White from bridge pickup to switch point 6 (these are the wires that will split the pickup).
Black & White from neck pickup to switch point 8. (these are the wires that will split the pickup).
Switch point 7 should go to ground.
Look at the picture below to see what I mean by “switch point” and what numbers they are.

28.
Here is a close up of the switch. It shows you what switch points I mean.
I'm not going to go too deeply into the workings of the switch, but it is a good idea to get a basic understanding of how it works so you can come up with your own wirings and most of all, so you can figure out how a switch that looks different from this one will be wired.

The switch will make contact with different switch points depending on what position the switch is in. And for the wiring we will do now, the switch points will do this:

The first position (with the switch all the way down) will be point 1 only. That gives us the bridge pickup in series.

The next position will be switch points 1, 2 & 6. 1 gives the bridge pickup, 2 gives the middle pickup and 6 are the wires that will split the bridge pickup, so we only get one of the coils from it (in this case the one closest to the middle pickup).

The next position will be switch point 2 only. That gives us the middle pickup alone.

The next position will be switch points 3, 4 & 8. 3 gives the middle pickup, 4 gives the neck pickup and 8 is the split for the neck pickup. You can choose which coil you want, the one closet to the middle pickup or the one closest to the neck by turning the pickup around. So turn the pickup around (180 degrees) from the way it is in picture 18 to get the coil that it is closest to the middle pickup).

The last position (switch all the way up) will be switch point 4 only. That gives the neck pickup in series.

It's hard to explain without writing a book, but I hope you get the picture of how it works.

29.
I will extend the wires that need to reach the switch by soldering them together with a piece of the wire we cut off before. Cover the extension with heat shrink tubing. It will be something like what you can see on the picture. The black and white wires are soldered together with a wire and covered with heat shrink tubing.
We don’t want the connections to come in contact with anything inside the guitar or it might short circuit the guitar. It’s not dangerous, but it will be totally silent.

30.
Here is how I do it. I soldered the black & white together with an extra piece of wire.

31.
Then I cover the exposed part of the wire with heat shrink tubing and heat it up with the soldering iron. I could also cover it with plastic tape, but I think tubing works better.
The reason we do this, like I said before, is so we won't allow any of the metal from the wires to come in contact with anything inside the guitar (except for on the switch, where we want it to make contact).

32.
We do this with all the wires that need to be extended: the black & white and the red one from both neck and bridge pickup. You can also see in the picture that I have soldered all the pickup grounds together (blue arrow).

33.
Now we start to actually solder it to the guitar.
A good trick to hold the ground wires in place while you solder them is to hold them down with a screwdriver, like I do in the picture. That will make sure that the wires don’t move when you take the soldering iron away.

34.
Then we hook up all the wires that should go to the switch.
Look at the wiring diagram so you get it right. It’s annoying to have to redo it because you soldered the wires to the wrong place.
I don't solder anything until I'm sure that all the wires will be the right length.
So I just put the wires through the holes in the switch and bend them around it so they stay there (blue arrow).

35.
When you know that everything will fit, solder them all down. Make sure they only connect where they should, or the guitar might give you some unexpected sounds or just be dead when you put the strings back on.

36.
A close up of the soldering. A small little bit of solder will do the job.
Don’t overheat it so you set the switch on fire. You can save that sort of stunt for your live shows.

37.
Here is how the switch looks from the other side when all the wires are in place.

38.
So the last soldering job is to get the wires from the output jack and the ground back again. Just solder them to the place that you removed them from.

Then just put the pick guard back on the guitar. If you don't trust yourself that you got it all soldered to the right place, then plug the guitar into an amp and see if everything works before you put the strings back on. Just tap gently on the pickups to see if they work when you flip the switch to all of its positions.

39.
The last thing to do before you are ready to go out and play with your new pickups is to adjust the pickup height. There are no rules that say you have to have your pickups 22.3 miles away from your strings, or it will sound like shit.
But it makes a big difference in what sound you get from the guitar, so try to play around with it until you find where it sounds best to you.

You might find that you get string pull from the magnets if you get the pickup too close to the strings. Magnetic string pull will make notes sound off key and kill the sustain in the guitar.
The thing you normally want to achieve is an even balance between the neck and the bridge pickup, so they are even in volume when you flip the selector switch. But it could also be set up for as much volume difference as you want if you always use one pickup for lead and the other one for rhythm playing.
Just play around with it until you find something that will work for you.

The picture shows roughly how close to the strings my pickups are. It will have to be fine tuned when I actually start to play the guitar, but they will be around this distance.