Rear tire

With car jacked up and tire is clear from ground
and all lug nuts off and you can't pull tire/rim from drum,
try this
screw lug nuts back on, and run about half way down
then, take a hammer and tap nuts but not hard enough to damage them, also tap with hammer on rim as near to the drum as possible.
I have had to do this on one of my cars.
The only thing stoping it from coming off would be
rust. If you can tap it just right it should come off
good luck