Rock Shox Spring Upgrade

[y2gt]

Hey all. This is my first post here....yup, I'm an annoying newbie!:D

I just got a gary fisher big sur with the 2003 duke XC U-turn Fork.
I weigh 190, and the fork seems to be too soft for me. I was reading up that I can get black (Firm) springs for the fork.

My question is, how easy is it to change these out? Do i need to get new oil? Where can I get these springs?

The bike shop said he could do it for $100....I always do everything myself (I hate bringing the car to mechanics), so I was wondering if I can do this myself for cheaper?

Thanks for any help. Sorry if this is a dumb question.:D

[gtbike]

Some tips- and oh yeah- welcome to the Monkey.

-Try a search i this great forum- chances are someone may have done this already.
-Try the rockshox website- it may have the tech manual for you fork. It will give you some instuctions and insight.
-Try the site www.angryasian.com he is forking guru.

Good luck- $100 sounds way steep for just the work- unless that includes all parts, oil and tax.