8 3/4" Questions
My friend did all that work himself. A sawsall is all that is need to to splte the tunnel. I did not see him do it but I am quite sure a BFH will work to move the metal. The hard part would be whether you have a welder and welding skills.
If you brought this to a body shop that is willing to do this kind of work I would plan on paying for 20-30 hours of labor.