91 Lumina Starter

I am trying to replace the starter in my lumina. What is involved in this procedure and what do I need to replace? The whole thing or just a small part of it?

remove neg battery post get under car and remove the entire starter and install new 1

I just replaced the starter in my wifes 3.1 lumina not long ago,It will be much easier to get at if you tilt the motor back because it is a pretty tight fit up in there.Also make sure you don't loose the shim if there is one cause if you don't put it back on the starter will not engage the flywheel right.Other then that it's pretty easy to do good luck.