Cant get brake drum off of 1997 chevy lumina looking for diagram for brake release

Ok, this is what I used to do when I was a mechanic at Sears.
I would get a medium weight ball peen hammer and hit the drum left and right sides until it got loose.

Make sure the parking brake is not engaged, of course.

This should loosen up the rust that builds up around the hub, and also press the drum brake shoes in a little so that you can remove the drum.

I've never broken a drum this way, and if it would break, it probably was worn out anyway at that point, was the rational.

Hope this helps.