How do I change the setup password?

Change SETUP Password #S
The default SETUP password for your modem is "MTSMODEM". If you choose to activate callback security, you should change the SETUP password using this command in the following format:
AT#Stttttttttt<CR>(where tttttttttt is the current SETUP password). Your modem will respond with "OK", indicating that you can enter the new SETUP password as follows:
You can select any combination of keyboard characters (upper/lower case sensitive) between one and eight characters long.