98 YZ compression adjuster you want to be careful with. You have to drill the 2 peens and then make sure you don't gall the threads when pulling it apart. You do that and your screwed. You can twist that one out with a wrench, but from 2000 up you need a special tool for them. Removing the shaft assembly from the body requires depressinig the sealhead and removing the circlip from the body. Once the circlip is out, just work the shaft up and out of the body. Bladder cap is also held in place with a circlip.
Let the pressure off the shock, depress bladder cap, remove circlip and pull the bladder out. Depress sealhead, remove circlip and pull shaft assembly out. Just watch it with the compression adjuster, I've known a few inexperienced guys to ruin their shock bodies pulling them out. If you have any doubts just leave it in there. While it may not be sparkling clean at least you won't run the risk of needing a new shock body.