How do you remove the rear brake cylinders on an '89 Chevy Celebrity for replacement?

Take the 2 bolts out of the back. After the 2 bolts are out hit the broken cylinder with a hammer to shake it loose, then pry it off with a sturdy screwdriver.

Remove the brake line with a flare nut wrench and the bleeder bolt. The bolts attaching the wheel cylinder to the backing plate are also on the back. I think this year model requires a female Torx bit, which if you don't have in your toolbox, you can get a set of three or four assorted sizes at an auto parts store or Sears. Unhook the brake return springs and move the tops of the brake shoes aside, but otherwise leave the hardware intact unless changing shoes or other parts.