easiest way to do it is to cut a little disc just bigger than the hole and place it under hole weld/tack into place little at a time wait to cool between tacks sand/grind flush i'd etch prime first then fill any perfections etch prime again flat and have it painted

Don't forget to etch pime under and and seal it with pait or brush on sealer

Paul

DON'T FORGET TO COVER ALL GLASS AND INTERIOR !!!