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.
From the home screen, tap the Apps icon.
Swipe to, then tap Visual Voicemail.
Tap the Menu icon.
Tap Change voicemail password.
Enter the existing password, then tap Continue.
Enter the new desired password, then tap Continue.