Use a hacksaw and cut the bolts through the slot. Obviously you'll need new loc-on collars after though. Or if you can be bothered to try and get the bolts out...just new bolts.
hi dont know if this helps but u can try drilling them out and just replace the bolts or hammer a torx head into the bolt they normally lock in pretty good
Hacksaw through the collars, then put in a fat screw driver, and force each side away from each other. That means you don't have to cut all the way through. It's how i got mine off a couple of days ago.
Then go and buy yourself some imperial grips with 3mm bolts!
use a grinder attachment on a dremel and cut through the space in the lock on collar. about a minute and its done. whip off the collars and get some new ones (or grips)