can't remember really how much room is in there but.
get a right angled screw driver and painstakingly 1/4 turn it out.
could you get a socket with a torx head into it and a small socket wrench?
Make a tool out of some steel rod!
get a very small socket and put a dab of silicone on it and glue it to it, leave it a day or so and then unscrew it.
Is it easier to get to from the gear shifter?
All i can think of.