there should be two quarter-turn fasteners on the bottom edge of each cover, one at the front edge, one at the rear edge. turn each one 1/4 turn counterclockwise. pull the cover down about an inch or so and remove it straight out. installation, as they say, is the reverse of removal.
Thanks to this fine thread I decided to try to remove the rear wheel covers (skirts) from my Insight.
Yes, they were easy to remove; not quite so easy to re-install. The attachment bolts aren't really bolts (in the traditional sense), but have what seems to be a reverse thread (very course) so I found myself turning them anti-clockwise for 1/2 turn, push in with force, then turn clockwise 1/4 to engage.
Is that right? Or did I miss something very basic? It seemed to work in any case and the skirts have not fallen off since, so I guess I got it mostly right.
Plus, for some reason, the attachment "bolts" have a small dia. hole on the end, as if maybe they could be safety-wired on so as to not be easily lost during a quick wheel change on a gravel shoulder, most likely in the dark (ref. Murphy's Law). Not sure how that would work though.
I have said this before ---- I would just emphasize the point: I recommend for everyone to practice removing and installing the wheel skirts 10 or 20 times. Get good at it. I've had 3 new Insights, driven them 142,000 miles, and never had a loose skirt. (I remove them often for cleaning, rotating tires, etc.) Many are the horror stories I hear about one falling off, usually from a service technician not installing it correctly.
The skirts and fasteners are designed very well, and they work great. When installing, just place it flat, 2 inches below it's target point. Then, while holding all edges in FLAT, slide the skirt upwards into place, making sure all tabs have been grabbed. It will stay in place by itself. It should look tight, with no gaps. Finally, insert each bolt and rotate clockwise a quarter turn. You can carefully "feel" the slight tightening as you turn the bolt. (use a giant screwdriver or the tool in your Honda toolkit)