Hi Bob,
Fork needs to come off and be stripped down, empty the old oil and be careful you don't damage the bushes inside. It's usually this order dust cap, spring clip, top bushes x 2 then fork seal...
If you go onto you tube there are some instructional videos about changing fork seals. It's not a major job but you need to be careful what you use to remove the old seals and dust caps. If you use a screwdriver you risk marking the fork and this in turn will slowly tear away at the new seals meaning you need to replace them again and again! Oh and remember to add new fork oil!
Best of luck!
Sam
March 2009