Doing any unauthorized work to your guitar will void the warranty.
This is the fourth wiring option on this website for a two humbucker guitar. Of those four, this is the easiest to do and just requires adding two toggle switches.
If you have a two humbucker guitar, the odds are good that you only have three switching options:
neck pickup only
bridge pickup only
neck and bridge pickups in parallel.
However, since you are reading this web page, you want more switching options than this don't you?
In fact, guitarist Trey Anastasio (of the rock group Phish) wanted a guitar that had more tone options than the typical three just mentioned. So, he had legendary guitar maker Paul Languedoc (the soundman for the rock group Phish), make a custom guitar which had many tone options with a minimum of switches. Eventually, Paul Languedoc made 3 such guitars for Trey Anastasio and each guitar uses the switching shown in this circuit.
This modification will give you these five additional tone options:
neck single coil
bridge single coil
both single coils in parallel
both single coils in series
both humbuckers in series
Note that in the diagram, (both Seymour Duncan and DiMarzio) the neck pickup has been wired with what I call an "inside-out" wiring. This was done so that when both single coils are being used, it will be a humbucking circuit. Another benefit of that wiring is that the active single coils will be the bottom neck coil and the top bridge coil, which I think sounds much better rather than having the farthest coils remain active.
Still, if you want that extreme combination, wire the neck pickup in the conventional way and wire the bridge coil in an "inside-out" manner. The two switches required for this are DPDT switches that have no center positions. As you know some switches have "center-on" or "center-off" middle positions but they are not necessary for this circuit and it is strongly recommended that you do not use such switches for this project.
Looking at the wiring diagram, you can see that most of the parts are already in your guitar and all you need to add are the coil-cut and the series parallel switches. You may have noticed that the series parallel switch has a jumper wire that is shaped like a 'z' and goes from the top left to the bottom right terminal. Remember to wire this too.
The coil cut switch was drawn as a DPDT switch but all you really need is a double pole single throw switch. So wire in a DPST if you have one, but if you can only obtain a DPDT, it is perfectly all right to use it.
Because Trey Anastasio's guitar pickups are always a pair of Seymour Duncan's, we made certain that we showed the Seymour Duncan pickup wire color codes (as well as the DiMarzio ones).
And of course, as always, good luck with the wiring.