Broken exhaust manifold bolts

I have a 5.9 mag that’s not in a vehicle. Any tips on how to remove these 2 exhaust manifold bolts that are broken? Motor was clean only 50,000 miles. So they were not all rusted up etc.... don’t know why they broke. Was like this when I got it. The one is broke off almost flush and the other one is broke off up in the threads pretty far. Thanks