The shrinking hammer will work to a certain degree. It depends on how "high" your problem area is. I sometimes use the torch and a rag soaked in ice water to pull them back. You start on the outside edge of the high spot and work your way in. I also have a heating/shrinking tip for my stud gun. It works wonders on the little ones, then finish with a body file. If the area is radically distorted and appears as a "bubble" from too much hammer work, I sometimes remove some material by slicing it in the middle with a thin cutting wheel, hammer and dolly it flat, then weld the split back. I realy hate using filler and sometimes go overboard to avoid using it. Hope this helps.