You can access the modem to change the password by typping in your browser 192.168.0.1. If this address does not work, you can try the default Hitron modem address 192.168.100.1. You will see the Wi-Fi section, then you will be able to change the Modem password
Have a great one !
It should be the same password you used to login to the modem, you can try the password you set for your WiFi password. If you are still not getting it to work then you will need to factory reset the modem.