if u cant get'em out then take ur head off and take it to a machine shop, the bad thing is that u will have to buy a new hg.
i JUST had my damn timing belt done (as in like 2 days ago), i don't have the time or money to take the head off and take it somewhere. if i can't get them out, i'm just going to drive it with the missing bolts and just get a new head and whenever the new head is ready, just swap em.