well, the SX's are basically all mechanically the same. I still have a SX-Ti fork on one of my hardtails...Only the left leg has any oil in it, the other side is either a spring, or elastomer. Leave the fork on the bike, unscrew the fork cap on the top, and get a bucket, and drain the old oil out by, yes, just flipping it over. If it's no big deal to ttake the fork off, then I do it that way, a little easier...and I get a chance to clean everything good too. You have to use the exact weight oil...so, find a good bike shop who can or has the stuff. I ordered a bottle through my local bike shop, and it's the official stuff Answer recommended. Email manitou first to be sure what to get. Then just pour in the new oil, and read that PDF from answer's site. It says how many MM from the top of the fork crown the oil should be. Just pour in until it's at the right level, then put the top cap back on and you're done. I bought a special metal ruler with only mm's on it for this purpose. Hardware store had some...
The newer manitou forks have much better instructions on tearing them apart. Modern forks do work much better than old early '90s models, but boy, it was nice to pup two caps off, pull out a skewer with rubber elastomers, lube them up, and re-install...5-minute job.