roof skin replacement

So im moving forward on my project of my 72 dart, picked up a donor roof at the spring fling, just wanted to get a few tips from the pros, i picked up some spot weld cutters with the centering pin. I've already encountered a few areas on the drip rail that i can't fit the 3/8 spot weld cutter into, what other methods do you guys use to get rid of the spot welds. any techniques to do this job would be appreciated.