If you don't have a manual, get one. I use Haynes: cheap, not perfect,
but good photos and specs. This should give you a picture of the brakes
showing the starwheel and the actuator (which prevents the star from
turning the correct way to loosen the brakes). It should give a
description of exactly how to do this...
I assume that the drum is 'loose' on the hub, it just gets stuck on the
shoes when pulling it off. Try this: get the drum as far as you can,
grab behind (or GENTLY pry on it against backing plate), and whack the
other side at the outside corner of the drum. This sometimes will apply
enough torque to it to dislodge it...
-Mike