Removing top side bed covers

I have a small gap on the driver side, between bed and that black plastic piece that goes on top of the bed on each side.

What I want to do, is remove it and apply some one sided sticky piece of foam between bed and plastic piece, to prevent it for scratching the paint.

My question is, does the plastic piece just pops off if I pull up on it hard enough?
I don't want to break it by forcing it to do something it wasn't design to do.

TIA

 

There are two small plastic clips, one on each end of the rail that must be removed (look at the inside of the bed at the top). Go buy a set of trim removal tools at harbor freight to help you remove them. After they are popped out then yes the cap just snaps off.
These tools are very helpful when dealing with all the push-pin type fasteners all over these vehicles.