Help with pushed in rear parking sensor.

[Serpent45B7]

Evening, iv annoyingly got one rear parking sensor that has pushed slightly in on my back bumper, iv tried getting my hand underneath the back bumper, sort of down the side of the rear crash bar to push it out, but I just can’t get enough onto it, to push it out, it’s not fully pushed in.

So is it a rear bumper off jobby? As it spoils the look of the rear of the car and annoys me every time I see it. It is the middle most sensor on the left hand side of the rear of the car.

Any pointers or help would be appreciated, thanks Lee.