Frigidaire fmv145kb1 over the range microwave needs to be removed. Most directions say to unscrew from the top cabinet. We did not have a cabinet there was a board instead. We were able to take the board out to see above the microwave. There is a piece of ply wood up against the microwave with some 2 by
4s on top. There are no screws that we can see that attach to the microwave through the board. The installation instructions show screws on top of the microwave, we don't see that. There is no screw on the side of the microwave either. Any clue how to remove this?