There are a few ways that you can open a stuck garage door from the outside.   One way is to use a wire hanger. Straighten out the hanger and insert it into the crack between the garage door and the ground. Try to move the door up and down with the hanger. If it doesn't move, you can try to pry it open with the hanger.   Another way to open a stuck garage door is to use a tennis ball. Place the tennis ball on top of the garage door and hit it with a hammer. The force of the impact will cause the tennis ball to bounce off and either push or pull the door open.   Finally, you can try using a piece of wood as a lever. Pry the wood between the garage door and ground, which should open up a gap for you to access the emergency release.