One procedure I've done on occasion is to work over the friction surfaces of the flywheel and pressure plate with a dual action oscillating air sander and some 80 grit sandpaper, just enough to break the glaze on the mating surfaces and leave a pretty uniform swirl pattern. It won't correct any hard spots or uneven wear, but it beats assembling things with a too-slippery surface for the new disc to grab.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!