1995 Toyota 4Runner Headers? Gaskets?

I have a 95runner with the 6Cylinder engine that everyone complains about the head gaskets overheating and leaking. I read off one blog site someone replaced the parts on their own for 250 bucks. That would be nice. I think my 95 may be headed that way and would not be under warranty. Can anyone give a basic explaination to an novice on how to access and replace the headers and gaskets?