Take a 3m 3 inch 3/16 or 1/4 grinding wheel and go down thru there carefully and grind the roof skin down carefully the metal will turn blue when it gets thin. It not hard just take your time and be careful not to grind into the drip rail.you can drill off the drip edge but it is extra work and hard to do unless the car is on a rotisserie.pm me if you need help..