Rear bumper cap install question

Trying to install rear bumper cap/overlay. I got these off ebay and they appear to be the same or a knockoff of the sparks parts ones. Anyways how easy is the back piece suposed to slip under the existing black trim piece? I saw robmotives install video and he basically pulls the whole trim piece up. I tried that and broke a clip so hesitant to pull on this thing again. Anyway i got part of it tucked under the trim but the rest is tight and im not sure how to do it without really prying on this thing. Just wondering if since mine are cheaper apparent knockoffs if they just may not work.

 

That doesn't look like a clip...I think it's attached to something and you're supposed to squeeze the sides of the slanted area to release