This article describes how to change the voicemail password.
INSTRUCTIONS & INFO
To change your voicemail password, you must know your current voicemail password. Note: If you have forgotten your existing voicemail password, you will not be able to access Voicemail until you reset your voicemail password.
Press and hold the 1 icon (enter current voicemail password if prompted). Note: If you wish to skip listening to unheard messages, press * to go to the Main Menu.
Tap the 4 icon to change your personal options.
Tap the 2 icon to change your administrative options.
Tap the 1 icon for password options.
Tap the 1 icon to change your password then follow instructions to enter a new password.