replacing rear lens cover - how to?

Hi - I'm new here and need some advice. I'm attempting to replace a cracked rear lens on the passenger side of my 2012 PriusC. I purchased a replacement on line and am able to get the old lens cover off and remove the bulbs. Everything is good except I need to remove the circular connector (circled in the photo) from the original and install it in the new one. Do I just rotate it counterclockwise to remove - tried to do that by hand and it won't budge. I could use a screwdriver for leverage but I'm worried I will crack the plastic. Any advice would be appreciated!

 

Figured it out myself - that round plastic thing is held in by the central Philips-head screw. Once the screw is removed there is an o-ring that keeps the round plastic thing from falling out. Need to pry it up around the edges (without damaging the o-ring seal) to get it to come free. The rest (twist in bulb housings and putting lens cover back on) was easy.