its not that hard to do yourself...just turn the amps down on the welder, and only tack...don't try and do line of weld otherwise you will warp the shit out of your panels...when you tack, make sure your alternate where you tack and try and give the it time to cool down before you tack again, but don't cool it with water or compressed air!
Also when your grinding the welds back go lightly otherwise the heat from grindering could also warp the metal...