I had the same problem. I attempted the dremel method but still wasn't able to get enough grab. I solved it by taking my cleats down to the local hardware store. They were able to bore out a hole using a drill bit, and then hammered a tap (not sure if that was what it was called, exactly. It was a tapered bit with four edges) into the drilled hole and used a wrench to apply torque to the hammered-in bit. It took a few tries on each bolt. I nearly hugged him when he got the first one out!