I rolled mine myself. I'm NO bodyman. My paint didn't crack or chip, but it's the original & I wasn't too concerned. But I did use a proper body work hammer & dolly, which I borrowed from a bud. It was an expensive hammer. Big flat surface on one side, pointed on the other. Started from the center of the fender & worked out towards the edges. No kerfs. The first one was not the best as far as being 'pretty' but it was a rear fender, & it didn't really need to be done.
I've gone through roadside vehicle inspections, & because the truck is 'modified', the inspectors have gone over it with a fine tooth comb. Several have checked for front tire clearance by running their hands along the inner edge of the fender opening. No complaints from them about the fenders, & one guy complimented the rolling job!
DO NOT use the 'Eastwood' fender roller! I've heard several horror stories of the damage they can cause, & actually seen the damage caused to one vehicle from that thing. The owner ended up buying a new fender. Usually 'Eastwood' tools are very good, but not the fender roller. The damage could have been caused by a person not knowing what they were doing with it, but I wouldn't take that chance.
