At one time member GT made an excellent set of tools for reworking magazines. I think he was a bit disappointed that folks did not realize how good and how needed they were. The following photos will show a GT swage and block tool at work for disassembling a magazine and removing dents. If you contact GT he may still have one of these or he will be happy to use his on your magazine for a reasonable charge. What is involved in doing this task right requires the right tools and techniques
first the before mag
the lower half
and the tools