Broken and unbreakable bolts HELP

Ok a little more information. I called a few machine shops I am getting quotes of 55-75 an hour. I can't do that right now so it is going to be up to me. On the broken bolt on the outside edge of the heat riser. I think I can use a pair of vise grips. I have been soaking it in PB Blaster every chance I can get. I have tapped it with a hammer to help also.

As for the rear bolt I don't know what to do. The bolt is not actually broke in the hole it rotted in the hole so it is below the surface of the manifold and it has a point stick up in the center. Makes it damn near impossible to drill dead center. I might try a dremel and grinding stone to level it out some.

I would love to replace the manifold as it has seen better days but it does not leak and I can't afford to replace it at this time.