Hi, never happened on 1345S but the QR have a quite straightforward push-and-rotate mechanism, In my opinion there is no alternative way to reach the locking area, not even if you disassemble the motor. How many flights? In my opinion you can't damage the motor trying to unlock the prop if you don't use an hammer ;-) just don't force it on the vertical axis, that could stress the bearing. I would just try harder, and in case you break the prop or the lock, it's a quick and cheap replacement. I would replace both the prop and the lock, after removing the prop and before the next flight.