Creating a subnet using the G-1100 and a Netgear R7000 Nighthawk

Hi, Our business just had FiOS with a fixed IP installed: 1 - Verizon G-1100 and 2 - WCB3000N units. Cat6 and coaxial cable run to the G-1100 from the ONT and cable splitter. Only coax is run from the splitter to the 2 WCB3000N units. Our office is split by cinder block walls into 3 areas. The G-1100 is in the center area and the 2 - WCB3000N units are located in the outer 2 areas. I'd like to have one of the outer office areas on its own network (replace one of the WCB3000N's) so they can have access to the internet via ethernet, wireless and VoIP connectivity but not see the other network. Is this possible using the Verizon G-1100? If so, can someone walk me through the steps on the G-1100 web interface to create a subnet for the Netgear R7000 office? Thank you. Your help is greatly appreciated! John