How do you get the rear drums off on a 66 catalina

Make sure the parking brake is off and the shoes are adjusted in so they don't touch the drum. Then apply a liberal amount of penetrating oil around the hub and through the lug holes and wait before trying to remove them again. If this doesn't free it then you can try heating the center of the drum up a little with a torch. Then you can carefully tap around the back edge of the drum with a hammer. You might also invest in a drum brake puller to make it easier. Be sure to clean all the penetrating oil off the hardware and drum with brake cleaner. Put a small amount of anti-sieze on the drum when you re-install it to prevent it from seizing on again.

make sure the nut is off and hit the face odf the drum with a 2lb hammer or bigger. you might have to do this once or twice but that should do it , or go to auto zone and rent a puller (its free) .

BFH adjust shoes in to the minimum and then hit it with the BFH