A panel swap looks simple from a video, but on a torsion-spring door the panel sits under real tension from the rest of the section once it's fastened in, and getting the hinge and roller alignment even slightly off will bind the whole door against the track. We don't recommend owners pull a panel themselves on anything built after 2000, since these insulated sections are heavier than the old single-skin panels and don't forgive a crooked reinstall. If the damage is cosmetic, a dent with no crease, no gap at the seam, and the door still runs quiet, that's genuinely a cosmetic call you can leave alone. Once a panel cracks or the seam separates, waiting just lets moisture into the foam core, and that's when a one-panel job turns into a two-panel job.