This article explains How to Change Wi-Fi Password In GPON ZTE F600W / F660 router. Its management IP is 192.168.1.1.
Step 1 : Log in GPON ZTE F600W / F660 router
Username : admin
Password : admin
Step 2 : Wireless Setup on GPON ZTE F600W / F660 router
Click Network -> WLAN ->SSID Setting.
SSID Name : Create a name (up to 32 characters), Click "Submit" to save your settings.
Click Network -> WLAN ->Security.
Authentication Type : WPA/WPA2-PSK
WPA Passphrase : Create a password (minimum of 8 characters in length)
WPA Encryption Algorithm : AES
Click the "Submit" button to save your settings.