Adam, I would drill the center of the bolt with a drill bit large enough to use an EZ-Out bolt extractor ... pick a drill size that will allow some margin for error if the hole is slightly off center, but large enough that a suitable size EZ-Out can be used to remove the bolt stub. You certainly want to avoid breaking off the EZ-Out so apply PB Blaster liberally before attempting to remove the bolt stub.

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Fred Hoelzle