Outer roof panel removal on a 72

[Rg500gamma]

I had purchased a used cab from out west and it was a AC and non roof cab lights. The dash was swapped and the original roof with the lights was also swapped over to the west coast cab. The west coast cab finally rotted to where the inner and A n B pillars rotted thru. I was able to get roof with perfect pillars and 1 small spot above the 1 door. But, no cab lights. Swap time again. I'm hoping it wasn't GLUED to the cab. So if it wasn't, is my best bet to put heat to the drip rails to get the sealer gooey and follow behind with a putty knife ? Then follow it with a rotary wire wheel until the spot welds are cleaned up for the drill bit ?