I will say this but once, and all you young 'uns take heed.
IF YOU USE AN EASI-OUT, DRILL THE HEAD OFF FIRST.
Because if you snap the easi-out in the bolt (Oooohhh yes, it's REALLY easy to do...), you will never drill the head off, because the easi-out is made of unobtainium, the hardest material known to man. Then you really are cactus.
You will find that if you drill the head off anyway, you may be able to slide the head over the bolt, and have easier access to get vice-grips on what remains of the bolt.