The pinch weld is pretty easy. I have a write-up in the "how to" section here.

The past 3 vehicles ive done the mod to I haven't messed with heating the liner. Instead ive used a self tapping screw to pull the liner back. Pretty sure I added that to the "how to" as well. A week ago I did lekmedem's pinch weld and just had to add a zip tip to the passenger side in addition to the screw.