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, press the Call key.
Swipe down from the top of the display.
Tap Visual Voicemail.
Tap Change Password.
Enter the current voicemail password in the Current password field.
Enter the desired new password in the New password and New password confirmation fields.