Field tricks to remove inside dually wheel?

You might be able to get a small steel chisel between the rotor/drum on the rim openings and give it a couple of wacks with the tire iron. it's worked for a couple of cars that had seized rims. Then apply anti seize to the mating surface, sparingly. Another trick I used on trucks if you don't have a heavy load, loosen the wheel nuts about 1/2 to 3/4 turn and make some really sharp left right turns, that often cracks them loose too.