Removing under cabinet GE microwave

Question

I have an old GE JVM130001 under cabinet microwave that no longer works. It was installed before I owned the home.

I can't seem to figure out how to un-mount it so I can replace with a new one. It is flush up to the cabinet above it and a cabinet to the right. Myself and another person diligently inspected all the connecting cabinets and could find only one s***w that seem to be connected to the microwave. We removed it and unplugged the electric cord. We have removed faceplates and any part we could to try to find other connecting screws. We have tried tugging and pulling all directions.  It doesn't budge. It is snug up to the cabinet on top of it and to its right. I literally cannot see how it is attached to the mounting plate. I am beginning to wonder if was installed with an industrial adhesive. Short of taking the cabinets down does anyone have any suggestions. 
Thanks in advance.