I think I once saw something that looked like a torx E type female socket on the end of a screwdriver that might have worked to unscrew the torx screw down inside the Bohème cap. It's possible I might have dreamt it but wondered if any of you repair experts out there have ever managed to unscrew the screw inside a Bohème cap?

So far I've tried extra long E torx sockets but even the 1/4" version fouls at the opening of the cap and won't reach down inside as far as the screw. Apart from getting the right E socket then grinding it down on the 1/4" end I can't think of any other way of getting this screw loose so if anyone has ever done it and has some sort of a tool for doing it please let me know. Thanks.