A:Answer Okay so this is tricky. You can, but you must first call Verizon and tell them to switch your current WiFi router into just a modem. Right now, your wireless router is handing out IP addresses to all devices on your network, if you hook another router up within that network, you'll create an IP loop (conflicting IP's) and it will mess everything up.
Once Verizon has turn off the DHCP/WIRELESS transmissions from their router, then unhook all connections from it and plug them into the N750.
So what it should look like is:
1) Cable wire running from wall to your Fios Router
2) Ethernet Cable running from your Fios Router to your N750
3) Any other hard connections running into the 1-4 Ethernet ports on your N750
4) Setup your N750 wireless router, then connect all devices to it.