Water pump bolt broke off

Then throw the whole car in the ditch. Why save what two hours worth of work can fix? Why are you trying to avoid pulling the cover? Are you trying NOT to learn something new? There's only one way to get the genie out of the bottle. Pull the cover and either fix it or replace it.

It's all part of hot rodding. Are you trying to get out of that, too?
I think the Mig suggestion is at least one other way to solve the problem. By the way....do you usually try to sound like a condescending prick?