Rounded saint crank bolt

Tried to take off my saint cranks at the weekend, but one of the bolts on the non-drive side crank arm is rounded, can't shift it.

Any clever ideas?

I have a few rounded allen keys that may fit.

try using a torques key and hammer it in to the rounded bolt.

tighten up the one you took out real tight first this should take the pressure off the rounded one

Cheers, will give that a lash.