K12 Side Skirts

How do the K12 Micra side skirts attach? Do they just clip on somehow? On the underside of my sills there are what appear to be circular fastenings of some kind, and I'm assuming that's what they're for, but can't work out how they are used.
is it easy? If so, I'll get some off Ebay and paint them myself. I'm assuming it uses special fasteners, which will probably be missing or broken on a second hand set. Can these be had from a Nissan dealer without remortgaging my house? Anyone fitted them on a car that wasn't meant to have them?
The car is a 2010 N-Tec, which I pick up on Saturday!! I love the look of the Acenta Plus, Sport and Tekna side skirts, and think they'll look fab on the N-Tec with it's side trims as well.