Ok this is for you that has had this problem before, as I've tried and failed for two hours to remove the jammed bolt that holds the crank in place on the raceface hollowtech 2 crank.Its not the external 15mm cap but the internal 8mm bolt. I've tried all sorts but am now open to suggestions that will work. PS drilling it out is not an option.

Thanks for any advice.

For those budding mechanical engineers out there, I'd just like to save you taxing your brains as I've managed to get the bolt undone using a torque wrench and ratchet as a make shift torque converter. Job done.