i just snapped a bolt off in the cylinder head where the upper coolant pipe bolts down. i've been trying all night to remove it and I've only made it worse. it snapped flush to the top of the head. i tried drilling it out and the drill walked off the bolt and made a hole next to it on the top. the only thing i could think of was to fill them up with liquid metal fill and try to drill and tap them tomorrow. so the question stands. how screwed am I?