How to remove a stuck on brake drum
If you’ve already tried the drum puller and it didn’t come off I would do the following.
a) remove the brake cylinder bleeder screw just in case some pressure is keeping the shoes out against the drum.
b) loosen the emergency cable adjuster to that wheel. Sometimes the cable is so tight that it will keep the shoe out and against the drum.
c) grind off the heads of the hold down pins on the backing plate for the primary and secondary shoes. This will free the shoes up and might let the drum off.
d) pull the rear-end cover, and remove the retaining clip so the axle and all comes off as an assembly.