Rear Diffuser Install

[seevisit]

I'm about to buy a rear diffuser for my M-tech bumper, and was wondering if anyone had any advice about the install. I see two bolts left and right at the corner of the bumper and then a row of flat pop studs on the inside bottom connecting the insert to the bumper. How do I remove these and is there anything else I should be aware of? Thanks!

[1996 328ti]

I use a blunt object and push the center of the pop rivets out.
Then I replace them with new ones since I usually can't find the center piece after removing them.