Are you saying that the wheel cylinder is stuck to the backing plate to which it's mounted ? If so, cause your not going to use them again, get a two pound hammer, some WD40, spray where they go thru the plate and start beating them up and down, back and forth. They are rusted in place. I replaced mine and they needed a beating to remove.
do a search on wheel cyls from a chevy. they are bigger in diameter and help stopping power.