Wiper arm install

[Skinny70]

I have total resto on my cab when I removed the wiper arms the bolts broke off in the cowl panel. I knocked the inserts out and cannot find them anywhere. Does anyone have any advice on reinstalling the arms and where I may find those nut inserts?

[cep62]

https://www.auveco.com/product/jack.html

A good hardware store should have them , or a good old school body shop should have SAE thread. (not metric)
But you could use metric , you just might confuse someone in the future.

They make an install tool,but you can install them with a oversize nut and a star washer.