Roll arches?

I'm thinking about rolling my rear arches, but how should it be done? (Not make the arches wider, only remove or roll the metal that points at the tire.) Should I use the same tool as should be used on the front arches, or do I need to cut the metal that points directly at the tire, weld, then smooth down and paint?

the rear arches are double skinned so if you cut yeah you'll need to ensure they are sealed, but the arch rollers you see out there should be ok to do the job just be aware the paint may crack

Arch roller is easiest. Can be rented or bought.

I removed the return lip altogether as my clipper kit covers the arch and the finish doesn't have to be perfect. For the rear I spot welded the inner/outer skins and applied lots of PU sealant.

Great. Should have done it before I got the car painted two years ago..