The friendly parts man at my local GM dealer resolved my problem so I thought I would pass along the info. BTW, the official name for that flip panel is Rear Seat Floor Filler Trim Panel. The reason I wanted to remove it was to see if it would fit on a 2013 Equinox which I recently purchased. On my 2013 I really missed that long in-floor storage compartment just behind the rear seat (that my 2008 had). So I wanted to replace that cheap flimsy piece of plastic with the flip panel from my 2008.
Anyway, the parts man showed me how to remove the panel on my 2008 by pushing a 1/16 inch drill bit into the tiny hole in the 2 pin (rod-end) retaining sleeves. Then I was able to lift up and remove the panel/rod assembly. I then unclipped the panel from the rod and clipped it on the rod in my 2013, and PRESTO
, my 2013 now has the 3+ foot long in-floor storage compartment with flip-open cover...... and I'm a happy camper