I did this the other week. I didn't quite understand what 76 cb550 was talking about either, until I had my fork apart and was looking at it. I took a 2 inch metal c-clamp and a stir stick for a 5 gallon bucket of paint (I am a house painter, so I had a bunch of these laying around.) The stick was 1/4 inch thick and maybe 1 1/2 inches wide and 2 feet long. The length doesn't matter though. Take the part of the c-clamp that doesn't move and isn't threaded and hook it under the fork seal. Take the piece of wood and rest the 1/4 inch side on the edge of the fork so that you can tighten the clamp down on the narrow edge of the wood. The goal is to use the wood as a sort of block so that when you are tightening the clamp, the threaded part of the clamp is not moving, but the other part is pulling up on the seal and thus removing it.
Sorry if this doesn't help explain it any better, I didn't take pics when I did it, and it is pretty hard to describe what is going on. It makes a lot more sense when you have the fork, the c-clamp and the piece of wood in your hands.