Darn anchor nut for front brake calipers got stuck. It's that nut that goes in from the back of the fork. I was attempting to loosen the nut last week and center the front calipers to the wheel, but the screwdriver head stripped the head of the nut and now is unable to grab a hold of the nut. It's one of those silly star head types and the nut is inside the groove of the fork. I tried using the Grabit tool to remove the nut, but to no aval. It seem to be removing more and more material off of the head of the nut. Any help appreciated.