I just picked a 2002 CR250 and it seems the shock has been leaking for some time now (not any dampening to it). I was looking at a service manual I have It doesn't seem too technically difficult to disassemble and replace the seals. I have done some technical work before(splitting cases). Of course I will be sure to let out the Nitrogen. What do you think?
The seal heads are sometimes hard to get out as they are very tight pistons, amd i like to bleed through the comp adjuster hole into a small reseviour(use a rubber grommet to go from a large hole to the smaller one of the res) to ensure all air is purged.
submerge the adjuster in oil and then fit it fast, you will never get all the air out and you dont need to-a tiny bit of air wont make a difference and new shocks are not well bleed IMO, people worry so much but the factory really doesnt do a good job and they ride that and never worry.