Take apart Nighthawk X4S AC3200 model C7800

Hi all, I'm trying to open up (disassemble) my Nighthawk C7800 modem and I unscrewed to screws at the bottom, but I still cannot open it. Is there a trick to this? More screws I missed? 

I would really appreciate your help and experience since I don't want to break it, but I have to open it.