tools required..
well......some sockets to take off the bolts holding the valve cover on.......posibly a flexible spackle blade (preferably not metal, as not scratch the mating surface)......some varsol or gasoline......
take off the cover bolts and washers/seal rings......
pull off the cover......may have to pry off..depending on how old.....a plastic spackle blade might do the trick...also use to clean the old gasket off both surfaces......make sure all gasket is off and OUTSIDE the valve area......gasoline is to clean the cover and bolts of oil and dirt....
IT IS YOUR CHOICE TO CLEAN THE BLOCK WITH THE GASOLINE....BUT I DONT RECCOMEND IT.....
re install gasket on engine...... you may decide to use a "form-a-gasket" to help with gasket seal.......
bolt cover back on......tourqe specs are in any haynes manual.........ive never followed them i just make it tight,......depends i guess on wether you trust your self not to strip any bolts......
if you have any more q's feel free to post...........i hope i helped........