Well, that's not really the right way to remove it. If you look at the drum there is a screw hole on it. You are supposed to put a screw into there and turn it until the drum comes off. That's why it's there...anyhow, make sure your e-brake isn't set, I would pop off the lid off the master cylinder. Then you can try to squeeze the rear pads in just enough to slip the drum back on.