1: In your browser go to http://systemcontrolcenter.com or http://192.168.0.1
2: On the left hand side, click on "Wifi Settings"
3: You will be presented with a logon screen, the default password is admin

4: Select either 2.4Ghz, 2.4Ghz Guest, 5Ghz, or 5Ghz Guest, which ever network you want to change.
5: Enter in the new password in the Password field
6: Click Save Settings
7: Once you have changed the password(s), you should reboot your terminal, and tell all your devices to "forget" the network, and re-enter the new password when connecting.