I had a self imposed hole in my front radiator from drilling a hole to run a wire. I will explain how I fixed it.
Revove the front bumper. There is a good post on this forum about how to do it. There are then two hoses and 4 bolts to remove the front radiator.
Once removed, spray the area to be patched with brake cleaner. Picture Shown. The guy at the autostore said it romoves the oily residue from the coolant. Then mix the two part epoxy and push it into the radiator as shown.