How to remove broken header bolts

[truegearhead]

So during my IMS/clutch job I snapped two exhaust manifold bolts on the left side. Luckily their both towards the back of the car so fairly easy to get to. One was exposed by about 1/2 inch and the other 1/4". After being turned down by nearly every exhaust shop in town as well as Lufteknic the local outrageously priced friendly Porsche shop who literally laughed at me I decided to try and remove the bolts myself. I started on the bolt that was exposed by a 1/2" and I soaked it in PB blaster for two days and then cranked down on it with some monster vice grips and couldn't get the thing to budge. I tried rocking it back and forth tapping it with a hammer etc, and now after 30 minutes of screwing with it its snapped off flush...

I really have no idea what to do now. I would really like to take and some where and am besides myself disappointed in Lufteknic, I thought after taking it there for a 300 inspection a few weeks ago they would be a little more receptive to at least giving it a try, but hey some company's you can count on some you can't. What do you guys suggest? Right now my course of action is to drill the bolts out which I really don't want to do.