Here are links to the webpages or tutorials to change your passwords:
UCLA Logon/BOL: https://logon.ucla.edu/
1. Select Change Password on the page
International Email: sharepoint.em.ucla.edu
1. Log on with your email credentials (username will be in the form of firstname.lastname@example.org).
2. Enter your old and new passwords in the form.
3. Hit Change Password.