I just added roof rails to my 2016 LRDS HSE. Those covers have tabs on the short ends that "spring" into holes in the rail. You'll need the smallest imaginable flat screwdriver or similar flat device (dull razor blade?) to try to compress the tab on either end and gently wedge/pry the end up. From there, you'll see how they're made and how they fit in their hole. Mine were plastic and rather delicate. If you're intending to reuse, reinstall, or sell the rails, you'll want to go slow, cautious and surgical. I would imagine those covers could break easily. When you get the first one, the other covers all behave the same way. Once the cover is removed, all you need is a 13mm socket and rachet to remove the bolts that hold the rail to studs. The studs are built into the body. If you don't put the rails back on, you'll see that there are cavities that you'll probably want to cover.
Yeah, I know what they look like as I’ve seen the video of how to install them.
So you really think that there is a tool imaginably small enough to get in the gap at either end.... and if you push down the clips will somehow fold in to the cover whilst I somehow lift the cover out?
I want to swap onto a new vehicle, sound like it might be easier to buy a new set of rails.