If the shoes are frozen to the drums and will not release, try cutting the heads off the "nails" that secure the shoes to the backing plates. Take a small angle grinder with a cutoff wheel, and grind away the head of the nail. The shoe and drum assembly can then be pried away from the backing plate far enough to get a pry bar inside the drum and dislodge the wheel cylinder pins. If things are that bad, you'll probably end up replacing everything inside the drums anyhow.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!