I have to leave the receptacles that are on either side of the cabinet but I will replace them with better receptacles and boxes. I'll just connect them together with a longer piece of wire that I can attach to the side wall, then to the back wall and then back to the opposite side wall to the 2nd plug. A false back wall will cover most of that.
As far as the plug for the microwave I'll first see if I can find the other end of it and disconnect it and then drop the receptacle from the top and remove it. If I can't I'll holler back and try a different solution.