Discovered when doing the second one that in fact all the fastenings, except the end ones are slide fit. A lot of videos suggest breaking the clips is necessary-I’m not so sure now having taken them off . I think they just slide fit with a fastener either end.
The bottom larger clips are slide on/off, 5 per side. Push them into the metal sill and slide the plastic sill over over them. The small white or black clips are basically the same as door card popper clips, 10 per side. You place them in the holders in the plastic cover sill and once the sill has been slid in to place on lower clips these pop in to the 10 holes in the metal sill/body. Trouble with these 10 small clips they break for fun when the sill is removed.
Did mine a while back. While the covers were off i had them repainted and PPF put on to protect them from stonechips. Not cheap but worth it as they needed painting anyway.
Thank you. My ND4 is brand new. You wouldn’t think I’d need any but I’ve been there too many times searching for hours through the odds and end boxes to replace the one that broke, the one that got squished coming out and the one that just ran away.