Swapping Magnets In Phat Cats

*Copied from http://www.mylespaul.com/forums/pickups/89982-p-90-humbucker-form-factor.html

Remove the pickup from the guitar and remove any mounting rings.

Remove and save the cloth tape around the bobbins.

Loosen but do not remove the 4 screws that attach the bobbins to the base plate and wiggle the bobbins away from the base plate. 
The cover will lift from one end only, the other end is attached to the ground wire & you can't lift it up.
If you look at either end of the pickup you will see the end of a metal rectangular bar. That is the magnet.
The magnets slide right out. Pull an old one out halfway, hold the new one next to it to orient it (ends repel, sides attract). In case you get confused, the magnets in all P-90's are positioned side-by-side, repelling each other.

Get a pair of tweezers or needle nose pliers and grasp the end of the magnet and slide it out. The wax may be holding it in place but it will come free if you shift it a little. You won’t break the pickup easily so don't be too timid with it.

PAY ATTENTION!!!
The edge of the bar magnet that is touching the stud bobbin must touch the stud bobbin of the other pickup and vice-versa in order to have the correct polarities on the bobbins. If you mess it up you'll have to do this all over to correct the problem.

Press the bobbins back down to the base plate, tighten the screws and re-install the tape.
The first time is the hardest, after that its easy.

Phat Cats: A2/A2

Neck
A5/A3: Brighter still, with less low end. Great in an LP, was a little chimey in an SG
A4/A4: 
A5/A4: Bright, clear, and well-defined. Compared to an A5/A3: more mids and a little less treble. Nice full sound. I use this pair a lot.
A5/A5: The classic Gibson P-90 pairing. Hard to beat.
A3/A3: chimey great for dark guitar 
A3/A4: medium to low output
A3/A2: 
A5/A2: Brighter with better definition than two A2's, but still a little on the dark side unless you have a bright wood.

Bridge:
A8/A4
A8/A5
A4/A4