Is there a tip to getting the rusted rear brakes off of a 1992 Lumina?
I know some WD40, a cro bar, a large C clamp and a set of TORX wrenches, and/or male sockets.
Replacving a master cylinder is usually pretty straight forward. Remove the brake lines, unbolt/remove the master cylinder, Re-install in reverse order. The hard part is bleeding the new master cylinder/brakes once you put it on. Caution: Your life depends on your brakes. If you're not sure you can do it right... don't. Get someone to help you.
tire iron, flathead screwdriver for prying off the old pads, and get a general 30 dollar wrench set from auto zone. youll be good. go to expert village.com they have a great free video series on changing the break pads, which will be very similar to your lumina. http://www.expertvillage.com/videos/rotors-replace-check-jack.htm this video will show you, and the rotors if you need it too.