The brake adjusters are on an eccentric cam that moves the shoes in and out in relation to the drum. Work the adjusting nut back and forth- - - -one direction will retract the shoe, and it might no be the same direction on all the cams. Penetrating oil and a little heat from a Propane torch might help. As in other situations- - - -"all things in moderation"!
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!