If you drill down far enough to get the head of the bolt off ( I usually use a 14 mm drill bit for this, after drilling a smaller pilot hole), the cam pulley should come off. Then the thread of the bolt should come out of the cam, as there's no longer tension on it, as long as some drop kick hasn't loctited it. I've done this plenty of times, especially on the AVCS 2.0 and 2.5 heads. there fffing tight from factory.