Dear user,
Hope the below steps can help you. To change the Wi-Fi password of a Huawei HG659, please perform the following steps.
1. The default IP address of a HG659 is generally 192.168.1.1. Enter the IP address in the address bar of your browser.
2. Enter the default login account and password of the HG659 and click Login.
Username: user;
Password: HuaweiUser.
3. In the navigation tree, choose Home Network > WLAN Settings > WLAN Encryption. In the pane on the right, you can configure the encryption parameters related to the Wi-Fi network and modify the Wi-Fi SSID and password in the text boxes marked in red in the following figure:

4. Click Save.
The username and password for logging in to the web interface can be found below.
You are advised not to change the username and password. Thanks!