Depending on what you have on hand roger, it might be easier just to get a panel shop to do that...its an easy job, I would do it my self with the mig, but i have a mig, I have fire proof blankets, grinders , paint..everything i need to make that a 5 min job...
As i said, you just need to be careful how much heat you put into the area at once..
But all it needs is a little tickle with the grinder where you choose to place your weld...and a few quick hits with the mig....