2012 wk2 Rear bumper cladding

So the wife apparently backed into something and scratched up the Rear bumper with the greyish plastic piece that attaches to just below the painted surface. Can it be fixed by just sanding the scratches out with a low grit sanding paper or does anyone know of a better way to buff out the scratches Fortunately none of the paint was scratched thanks for any advice on this issue