How do I remove rear bumper cover?

[GasperB]

Morning all.

I have a MK7 SWB fwd van with rear parking sensors fitted. One of them is faulty but I can't get to the back of it to remove it. I'm assuming I have to take the rear bumper cover off. (Like the rear step cover thingy). Do I have to drill out the rivets on the top and the bolts from underneath?

(If so, why did they bother with bolts underneath if I have to drill rivets for the top??)

Cheers

Gary