Removing 2014 SE hatchback tail light bodies?

[area man]

I've been trying to figure out how to get these off so I can clean behind them. I removed 2 nuts from each via the panels in the trunk and disconnected the bulbs, but they are still being held on somewhere. Does anyone know if it's necessary to loosen the bumper to get them off? If so, which bolts/clips do I need to take off to do that? And what style of pulling tool do I need?

All kinds of tree crud is getting lodged behind these tail lights after flowing off the roof and around the hatch. I was able to pull some of it out, but I can't reach the rest unless I get these off.

http://i.imgur.com/sN74kQm.png

http://i.imgur.com/w9Qai6B.png

the style of clip in my rear wheel wells:

http://i.imgur.com/Z4EBNdD.png

thanks for any information!