Grind the area clean. Grind the stud clean.

Get some fiberglass cloth and some EPOXY resin.

Mix the resin as per included instructions.
With good scissors, cut a circle of fiberglass cloth about one inch bigger in diameter than the base of the stud. Cut a slit in the fiberglass cloth for the stud to poke through.

With a 2" paint brush, apply some resin to the spot where the stud goes. (how to align it is up to you)
Apply some resin to the base of the stud and set in place.
Place precut fiberglass cloth down over stud and pat into place with resin soaked brush. Get the cloth completely wet out with resin. Allow the resin to cure and you are DONE!!!
Wear rubber gloves and work in a vetilated area, and/or wear a respirator.
Allow the brush and the resin to cure also then dispose of it.

GOOD LUCK!!!!