If you mean the top chrome bit just get a flat head screwdriver under it and prise it from one side to the other, should feel all the clips pop, then goes back on by pushing it down.
If you mean the s-line (gmbh) lower exhaust part within the valance it's all one piece so no chance.
If you mean the entire lower valance then think it's just clips too, may need to drop the bumper aswel.