If the fuel shut-off valve is stuck closed and you are unable to open it, you will not be able to drain it at the fuel line as previously suggested. You will either have to siphon the gas out, or, remove the valve and catch the gas in buckets. This could be very dangerous. Disconnect the battery and move the car outdoors.
Personally, I would make another attempt to get the valve to open. It may just be tight, not stuck. Try harder.