I did the exact same thing. I tried to use an Allen wrench, but those bolts have locktite on them. A hex socket attached to a socket wrench did the trick. I stripped one of the bolts so bad, it was hopeless. SOOO...off to the auto parts store for an "easy out" kit. The kit comes with a drill bit and another bit. I drilled a hole with the drill bit, hammered in the other bit, then used a socket on the second bit to remove the bolt.