To change a password for a mailbox using the webmail client use the following procedure
1. login into webmail by going to http://webmail.habesha.net or http://webmail.yourdomain.com
2. Navigate to options at the bottom left hand side menu
3. Keeping to the left hand move to the top and select login
4. Enter your current password, New password and then confirm the password before pressing 'Update Button'