it depends on the location of the bolt. i normally start with a small bit, then incrementally work my way up bigger bits until the head falls off, this will be slightly smaller than the threads, they should be thin enough to bend by now. you should then be able to pull it out relatively easy by hand. just be careful not to drill out the female threads.

is the head of the bolt countersunk? i would try using a pair of vice grips first, if you can grip the top of the bolt. you could also try heating it up and using vice grips.

 

If you can get at it, what i usually try first is to cut a slot in the top so you can turn it w/a big flat blade screwdriver.

 

+1 to rrasco and Fathead..

 

finally after like 2 hours i managed to get it off.. i ended up buying a set fromm auto zone just hammered it over the bolt and with a socket attachment turned her out.. thanks for all teh help