Everyone who’s ever done automotive bodywork knows that once sheet metal is dinged, it’s essentially stretched and you can’t just push it back flat. Trying to push it flat will cause surrounding area to buckle the opposite direction like an oil can. You can work it to shrink the metal but that could involve hammering or heat, and since I presume the existing graphics needs to be retained, the only practical solution is to live with it, it’s not all that bad and I can tell that this unit isn’t exactly mint anyways.