I have a mountain bike with a 2003 Cannondale Lefty DLR Ti fork. As I've been riding the bike this season, I've noticed that the fork is behaving strangely. It doesn't seem to lockout fully and it is a lot "squishier" than it used to be. Also, when it decompresses after a hard compression, I notice a strange noise -- it's hard to describe but it sounds almost like gurgling fluid. I've already tried adding air to the fork using a shock pump (the pressure was very low) and that did make it a little less "squishy" but it's still not working like it used to.
It seems to me that it's time to do some serious maintenance on the fork; possibly even a full rebuild. How complicated should I expect this repair to be? What specific skills and tools will I need? What is the procedure for doing a rebuild?
I would like to evaluate the level of difficulty of this repair so that I can decide if it is something I'd be comfortable doing myself.