If you know your password, you change it in the same way that you change a temporary password supplied by ITS (e.g. when you first get your username or if you get your password reset):
When you change your University of Otago password, any device or application that stores your password (e.g.desktop computers, laptops, or mobile devices) will still try to use your old password to authenticate. Make sure to log off and log back on your desktop computer and email, and manually change the password on your mobile devices straight away. Until all your stored logins are updated with the new password, your account may be locked. If your computers and devices continue to use your old password, your account will stay locked until they are updated.