1967 Volkswagen Beetle wheels locked up

If the parking brake was on the whole time, the front wheels might be easier to free first.

If you've already tried taking the wheels and hub nut off and tapping (not too hard) from the back edge of the drum, there is a brake drum puller tool you might be able to get ahold of.

It might help to turn the star adjuster through the slot in the back of the brake plate to back the shoes off from the drum. Use a small screwdriver to raise the holder off the star so you can turn it with a bigger screwdriver or adjusting tool. If the star adjuster is frozen, squirt it with Liquid Wrench. The outer wheel bearing will come out with the front drums, and in fact, it might be part of your problem.