How does the Reverse microwave work?

"well the reason this has not been answered is that there is technically no such thing as a reverse microwave, so if you find an answer sell it to some company like GE and make millions"

That's not quite true. Yes it is true that there is not a reverse microwave as far as process goes. There is a device which is being worked on currently that uses magnetic fields to put molecules from a chaotic movement (heat) into a more ordered movement (cold). This link has a lot of information about magnetic refrigeration.