Rear bumper removal

Hi Folks

This is my first post to the forums, so apologies if i've posted in the wrong area.

It looks as though I have a fault with my parking sensors, i'm getting a beep when i put the GLC in drive or verse and double red bars. As a result last weekend I caught my the side of my rear bumper. The damage is only on the lower black textured section. The paintwork is fine.

I have a couple of questions:

1) is it easier to remove the entire bumper to replace the lower bumper / diffuser section.

2) If it is easier, what is involved in removing the bumper? For example do i need to remove the rear lights etc. What fixings do I need to be aware of.

I've done plenty of work on my classic Saab in the past, but I don't want to damage the painted section because i've missed something.

Thanks

Julian