1. Click on this link to open theCloud Outlook Web App: https://webmail.thecloud.net.nz
2. Login using your mailbox details
3. Click on "Options" located in the top right of the page
4. Click the "Change your password" button located on the right hand side of the page
5. Follow prompted instructions and click "Save"
Hopefully this has been helpful in aiding you to changing your password.