It's kinda tricky to avoid messing up the threads in the head, but Jerry was kind enough to show me the right way to do it. Do not use the screw-type EZ out, it can crack your head. Get the pound-in EZ outs. The studs are hard, you have to use a punch to tap a small depression into the exact middle of the stud, drill a small guide hole, then drill the proper hole for the EZ out. Be careful not to drill too far in, and remember that one of the studs backs up into an oil passage (the bottom middle one??)

Jerry removed the two broken studs in my head for me when I took it by for him to look at it, but I managed to break off two more when I was putting the exhaust manifold on, so I got a chance to try it out and his method worked well.