Hello,
Changing the Wi-Fi password of your Belkin router
Launch a web browser.
Enter "https://router" or "192.168. ...
You will be asked to log in using the router's admin password. ...
In the left navigation panel, click Security.
NOTE: The PSK must be 8 to 63 characters in length and is case sensitive. ...
IMPORTANT: Take note of the code shown in the Key 1 field.
Thanks.
For more to go:-
Belkin N300 Wifi Range Extender
Belkin Wireless Router Setup