Basically I noticed after a few weeks of buying the car of someone that two of the bolts that hold the valve cover on, were not in at all, and have obviously been snapped and part of them is still screwed in the head . I can only guess this was done by one of the mechanics who fixed the head gasket, and looking through the receipts it looked like it went in for a few things to do with that like black spots and stuff. What I need to know is what I need to do to get these bolts out of the head (or whatever they are in), any input would be great, nearly forgot to say its a B16Z6, 93.

Cheers