Take a big sturdy flatbladed screwdriver, the kind with the square shaft, and pound it into the lock as far as you can with a big hammer. Take a crescent wrench, size it down to the shaft, put a piece of pipe on the end if you need more leverage, turn in the direction the lock would normally turn (usually clockwise). It should break the lock apart (they're just pot metal) and turn it far enough to get the door open. No drill needed.