The axle nuts are NOT left hand thread -- they are torqued to something like 175 ft lbs and held on with a cotter pin, so are normal RH thread.
You need to buy/borrow/rent a rear drum puller that pulls on three (or five) of the studs to remove rear drums. I believe SI sells them and some tool rental places will have them. You cannot get the rear drums off by pulling (or beating) on the drum -- all you'll end up doing is damaging the drum. This kind of friction drum attachment system and puller was in common use into the 1960s, so you might find an old-timey garage that will loan you one.