Open the tailgate and u will see two big screws, undo these, then under the bumper u will see two 10mm bolts, take these out. Next in wheel arch u will find a screw on the bumper edge and poss. one just underneath, take these out. U may also find on the arch liner what they call a mushroom plug which u will also have to remove with a screwdriver. Pull the arch liner back slightly to gain access to the final two 10mm bolts which r up where the bumper joins the rear wing. Hope this is of help to u.
Brian