I got it out. It didn't have plugs, but it did have screws. They were hidden behind wood grain look contact paper. You can see in this picture. In the picture below, the two screws to the right are removed. The third one over I've cut the contact paper and the fourth one is still hidden. NOTE: I had to remove both bottom and top trim to remove the convection oven.
This is the picture of what it looks like inside for those of you who might be interested.
It had relatively long wood screws holding the trim on: 4 on the top board and 4 on the bottom board.
