How do I repair/replace this sheared bumper mount stud?

[JamesDean]

So while we were removing the potential replacement bumper for my 190E one of the four studs sheared off the bumper. At the time we thought it would be fairly simple to fix so we really didnt think anything of it however upon closer inspection...

It seems like it might be more involved. I was hoping that you fellows might have some ideas on the problem.

We initially were going to cut it off, drill it out and weld in a replacement bolt however it appears that the metal is aluminum.

I guess I could just talk to the body shop and see what they think about it since they're going to be the ones painting and installing it.

I'd much rather they paint/install this bumper over my current one as my current one is from a pre 1989 car and is the incorrect style for my model year.