Help! Wiper pivot stud broken

Hmmm 2 button head studs pressed into a horse shoe shaped plate ( That to beef up the weak sheet metal ). Just 2 tiny spot welds, 1 north east of left stud at perimeter of horse shoe plate, the other south west of right stud at perimeter of plate. If we go to banging hard on the stud, sheet metal distorts. Spot weld(s) fail? Cause hole in sheet metal that the pivot base seal doesn't cover. The left weld wouldn't but the right weld just might.
There's just nothing really sound enough to beat on so I wouldn't go there with a hammer.
I would first drill out the stud. Center drill then 1/8 drill, then 1/4 drill.
Then I would use a small square file ( little hobby file kit from Harbor freight comes in handy ) to make that a square hole that accepts the square shoulder of a 1/4-20 x 1 or 1.25 carriage bolt. I might consider a push on keeper underneath too but that could interfere with the pivots mounting.
A gob of silicone under the head would hold the bolt in place and prevent a possible leak too.
Good luck which ever way you go at it.