Desoldering Epoxied Components
Epoxy "potting" cannot usually be melted. You need to chip away at it. See How to remove &quot;glue block&quot; from PCB? However heat may help soften it so that it's easier to chip away.

If you can figure out what type of epoxy it is, an appropriate chemical solvent might work. For some epoxies, you can find good removers that preserve the stuff under, but it depends a lot on the epoxy used. E.g. this remover can even preserve biological samples, but it's for the epoxy used in electron microscopy. More aggressive, general purpose removers like methylene chloride or "Circa 1867" paint stripper will also damage electronic components and the board.