From folks feedback, people either loved or hated the experience of putting them in- As you've probably seen, it almost always revolves around those clips re-closing as you're working around the instrument panel.
The canned-air is a great suggestion, as well as a cleaning cloth for fingerprints, and anything you can get ahold of that has a slight wedge to it to keep each clip open as you move on to the next one. If you have several such wedges, you might be able to work around it in one shot, as some have done. One of the last posts said it took just 20 mins!

PS- The site you linked to seems to have all the same interior accessories as www.Bimmian.com, even all the same photos. I think some of those same products are offered at better prices at Bimmian, but perhaps I was recalling specials from their site.
Good luck with the rings!
M1