i thought about that but the bolts are tiny, it would be impossible to get a drill small enough to go straight in the middle, and i know in my set anyway, there isnt one small enough to go in it

Thats the best option.  Although they are called torques drivers, and you use a ratchet driver to turn it.  You will find that a torques bit that normally won't fit a new allen headed bolt, will fit a worn bolt perfectly.  I definately wouldn't try drilling it, as it's a stepped hole.  You could ruin the calliper Take it to a shop if mole grips or torques bits won't fit.  Last chance is send it to hope, they may even service the calliper and brakes!  I sent a rear wheel back to get a new ratchet fitted, and they changed the whole freehub, at no cost.  Worth a try!