I need to know what the trick is to removing the back drivers side rear brake assembly.

I went to back up today and the drivers side of the rear of the car jumped up in the air and will not move. It is like the rear brakes are stuck on that side only. I have having difficulty removing the rear hub on the car. I have the car jacked up and the wheel off but I can,t get any farther. Can you enlighten me on what I am missing? Thank you.