8.1 Workhorse exhaust bolt broken

As already noted. The easy way is to remove the manifold. Then hit the stud on the end with a hammer. That will shake it loose. Clamp on with vice grip and take it out. Those advocating changing the manifold gasket are at least 30 years out of date. Exhaust manifold to head gaskets are a thing of the past on OEMs. Before reinstalling the manifold, have it surfaced at the local machine shop. Then rub the exhaust ports down with a wet stone and mineral spirits, to clean them.

Richard