......... not sure how you get the chrome trim off
It comes off from the bottom (underside) I have had most success with a rather brutal sounding method, I use common household pliers with a bit of thin card (Weetabix box is good) wrapped round the trim before the pliers are applied to save scratching it.
Then, using a gentle grip, I rotate the pliers upwards, just enough to get the lower edge off, start at bottom of the A post and work up to the corner, then move to the back of the roof and work forwards so the corner comes off last. It's a bit of a black art, all done by "feel" and impossible to describe in words exactly how much torque needs applying to tread the fine line between not getting them off and damaging them irretrievably in the process! As with all things, practice makes perfect, I learned the art removing already damaged (by roofrack) ones on a couple of cars. Now I have it down pat and have at least 3 spare pairs if you cock up, though shipping them is a bit problematic!
Putting them back is fun too, the method I favour is painful, but effective, I thump them on with the heel of my hand! I've seen sissies doing it with a rubber hammer, but that's a bit vicious for my taste! Too localised an impact and harder to control the strike accuracy. It's gobsmackingly easy to dent them and almost impossible to get a dent out successfully.