Kristen,
Doesn't your garage door opener have an emergency disconnect that will disconnect it from the drive? Mine does in case the power goes out and all I do is trip it and the door is easy to raise up and put down. It should have a way to disconnect it from the gear. Otherwise use Fred's advise except hook the chain to the door and use a come along to pull it up. Or even easier. just start the car up, rev the engine, and drive right through it.
We are supposed to have rain starting here tomorrow but it was in the low 80s the past two days.
Ron
