This article explains how to factory reset a Netgear router and how to easily reboot it. It also describes other solutions you can try when your router is not working.
How to Factory Reset Netgear Nighthawk Router
With your router turned on, look for a small hole on the back. Use the straightened end of a paperclip to press and hold the reset button in the hole for seven seconds.
Wait about 30 seconds for the router to reboot to factory defaults. You can then log into your Netgear router using the default username and password found on the bottom of the router.
Rebooting a router reboots the device without affecting its settings. When you reboot the router, you should also reboot the modem.