Bumpers Shellz install question

Was going to put my black bumper shellz on today. It was only in the mid 40s and I tried to yank up on the black top bumper strip as shown in youtube videos to unsnap and lift it so I could slide covers under. I gave a good couple of yanks and felt like the strip was going to break so stopped. Figured maybe it will be easier next summer when it's hot out. Any tips? Should heat help or was I just not yanking hard enough?

 

I stuck a flat head under to get some leverage. If you look from the bottom you can try and squeeze the plastic ends that go into the bumper frame to aid in the removal.

 

Thank you. I will give it a try

 

The black top section is a major pita. It feels like clips will break, and they might.

Ive had that top section off a couple times now. Last time one of the clips broke. Goes back in place fine.

 

I didn’t pull off that part, I just slid it under, using one of my plastic pry bars to work it under gently.