You need to remove (2) T55 Torx head sockets you’ll see located just above exhaust tips.
Then remove (2 ea.) 8mm screws in well behind each rear wheel.
With a person on each side, the bumper slides right off.
Install in reverse. You’ll see a bracket on each side, just be sure to line up the slots.
T55 Torx is not easy to find. Check with Snap-on, Matco, Mac Tools or NAPA.