Remove the Torx 25 bolt from the front of the rear arch and pull it away slightly to reveal the plastic rivet.
Lever out the middle pin of the rivet and then remove the outer part of the rivet.
Pull away the sideskirt from the tridion - this will take some force and some of the sliding clips may break (so be sure to have replacements on hand). Smart part number Q 0001791V000000000.
Remove the 4x Torx 25 screws from the door shut (seen on this page) so the front wing panel can
be pulled away enough to gain access behind it. Behind the wing you will find this Torx 30 screw...
...and another Torx 30 just above it. With these removed you can take the plastic carrier section off of the car.
This will reveal another plastic rivet. As before, lever out the centre pin and then remove the rivet body.
You can now (using the force of almighty god) pull away the last two clips (which will almost certainly break).
Underneath the skirt are 5 more plastic rivets in recesses. Lever them all out.
The skirt will now pull away from the car.
Dave then had them colour coded and refitted them in reverse order to that shown.
The result looks really good.