How is the trim below the bumper attached?

[DWPC]

My wife managed to hook the black plastic trim beneath the bumper on the passenger side on something in the garage when backing out and broke whatever holds it on. The trim piece that goes around the Frt Rgt corner now sags about an inch. I see a plastic "tab" that seems to be broken in there, but can't see anything else without taking it apart, and I don't want to do that until I know its a DIYer. I'm hoping its just a std GM trim fastener. Does anyone know how the trim is fastened there and how hard it is fix it?