Heat should work. I use a plumbers torch and don't blast it with the heat all at once. I like to use propane, not mapp, and apply the heat for a few seconds wait a second apply more, etc... I found it you use too much heat all at once strange things might happen to the finish etc... Better to be gentle. And might want to wear leather gloves.
Life Member, ISRA Member, American Gunsmith Institute Certified, NRA
Instructor, State of IL authorized Carry Concealed Instructor [url]