awesome buy, with the studs i have taken some out myself you just need a stud extractor kit (auto part shop for about $20) and a sharp drill. just take the manifold off and drill a pilot hole in the centre of the snapped off stud, don't go too deep or you'll hit a water gallery, about 3mm or so should do it. then get the stud extractor and what i did was put it in my electric drill and run it on low speed in reverse, get it to bite into the pilot hole you made earlier and it should just turn it out for you. you may need some wd40 if the stud has seized to the head a bit.
its hard to explain but there ya go, and here's some pics