[dsraven]

if you have an old steam iron that puts out pretty good heat still you can try that like a shrinking disc. the nice thing about the shrinking disc compared to a torch is that it only heats up the high spots and a torch is also easy to overheat. heat and use a wet rag or sponge but only heat enough to make steam when you apply the rag. an iron will likely take longer but probably get the same result. it really comes down to getting the sheet metal work as smooth as possible first. hammer and dolly technique is a good skill to practice on with some old panels. there is a good little read called "the key to metal bumping", it's an old book but teaches some techniques of how to start removing a dent etc. there is an online pdf for free I think.