Trick to removing the trim fasteners...
Fit a T20 Torx bit in an electric drill (or electric screwdriver), Bump the bit deeply into the trim clip and gently 'unscrew' it easing the drill outwards gently enough so as not to pull it from the plastic centre of the clip. If they won't unscrew help the centre portion outwards with a flat blade whilst unscrewing as above.
Most of all ignore the hex key method of removal as the hex key hole will only round off!
Re-fitting is simply by knocking the centre plastic centre pin in when the outer is firmly in place.
The front transverse roof trim strip can be slid out to the side sideways if a top section of a 'B' pillar is removed, I can't remember if the rear one will come out the same way.