[Eliot Ness]

I like to perform these not so delicate operations outside. Turn upside down and tease with the propane torch all around until the crap drops out onto the newspaper or whatever you have thoughtfully placed beneath it........

That's the way I like to do it because it's fairly quick. That and I like the satisfying sound of the potted glob as it lands on the newspaper or other container

I think the last time I used a heat gun on a potted capacitor assembly in an Atwater Kent, but it wasn't quite as easy as the torch method. Some guys even go to a thrift shop and buy a used toaster oven to heat these up. Like codefox said, there are a lot of ways, just do a search and find one that works for you.