Left rear tire keeps locking up

[avguy]

Are you planning on replacing the drum? If so, just punch a hole in the face, between and slightly outside of 2 of the lugs. One way is to send a fairly large drill bit in a few times, and then connect the dots with a dremel or angle grinder. Or maybe just cut the opening with the grinder, without punching any holes first. Then position the opening at around 10 o'clock, varying according to how big and where the hole is located. The idea is to create a large enough opening to be able to get the tip of a screwdriver onto the adjuster wheel. Doing this wouldn't be necessary if the manufacturer had cut the standard slots in the back of the drum, as they should have done.

But if you're not planning to replace the drum assembly, the only other thing I can think of is trying to get lots of WD40 inside of it, in order to make it easier to slide out. Good luck with that one!