Dare devil has a point.... I would let the stud cool tho and heat the head some myself.. Not sure if cast works different but anyway it should loosen it up after it cooled just the heat making it expand and then retract will or should let the bolt stud break out a lil easier... The hammer and punch works too... If it is just the tip and that small it should bust up pretty easy... back in my roughneckin days Ive seen many busted up and picked the pieces out or use air to blow smaller pieces out of the hole.. Dont give up on your head man it is fixable...
