The fixings that you can't get to with the door closed are the four little screws, two on each side of the door card. If you have taken the internal door pull, internal handle surround, window winder, mirror adjuster knob, door mirror internal trim and the lock pin all off and you are prepared to sacrifice the side fixing screws, you can force it off.
Even if you damage the door card, replacements cost next to nothing. At least you'll be in.