Hello.. here are the step by step guide:-
Launch a web browser from a computer or mobile device that is connected to your extender's network. ...
If your extender and router use different WiFi network names (SSIDs), type www.mywifiext.net into the address field of your web browser.
Click or tap Enter. ...
Enter your admin user name and password...
Click or tap Login.
Click here for more information at Netgear Range Extender Login | Netgear Wifi Extender Login