Not exactly sure about your specific fireplace. However my coachman fireplace is pretty straightforward to remove.
There is an outer trim piece that just slides upward and can be removed. The trim piece on mine is an upsidedown U and acts like a bezel that covers the outer edge of the fireplace. So you lift the entire piece of trim up and pull it away.
This exposes the mounting screws that hold the fireplace box into the wall. Once you get the screws out you can remove the entire box and unplug it and begin to test it
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