how to replace a head gasket

Your best bet is to go to auto store and purchase a Haynes repair manual for your vehicle. If you want the actual repair manual for your make and year produced by Saturn, try Amazon or Ebay. That will cost you more. Too many steps to list here. Plus manuals have step by step pics.

http://www.ehow.com/how_7858967_replace-head-gasket-saturn.html ..I disagree on part of their article, where it says "keep track of where each head bolt come out so it goes back in same place" No, use NEW bolts

Reelin68 is right on. Too much to put here and that article is way oversimplified, do what he suggests but the ehow is a glimpse of what you're getting in to, and don't even start unless you have a decent tool kit