You may need to access your router to change the settings or password.
To change the password you need to locate your routers IP address. The IP address can be found under the router or on the manual.(examples of an IP: 192.168.0.1, 192.168.1.1, 10.0.0.1, 10.0.0.2)
Open your prefered internet browser and enter your routers IP address in the search bar. Hit enter to search.
Enter the administrator password, then click 'login'
Depending on the router you are using you click 'Wi-Fi' or 'Wireless connection' on the left side.
Select 'Manual Wireless Connection Setup'
Enter your desired name in the 'Wireless Network Name' field.
Change the password in the 'Pre Shared Key' field.
Scroll down and enter the same details for the 5GHZ Band.
Scroll down and select 'Save Settings'.