No-no! It's a 1997. It's a 1997. The '98 and '99 both had RST's, This is a stock fork. Damn it, I should find those old catalogs!
Anyhow, I don't know what you mean exactly what you mean with "free it up", but this is what I'd do:
- spray some WD-40 on it, especially the bolts, so they can loosen up easier
- let the stuff creep in for like 15 minutes or more
- take it apart by means of a hex key and what else you need
- clean it
- grease it up with some quality grease
- put it back together
I am no expert mechanic and I don't work much on my forks (I have friends to help me out), but this is a simple fork and you shouldn't have many problems with that. Just make sure to have the dials without any preload before you start taking it apart. I would also look up an owners manual on the internet. If you can't find any, bear in mind that the chassis was the same for the more expensive forks (SX, FS, SX Ti, FS Ti) from that year and the following two.
Cheers,
Mx