To reset a password from the UC Client, log into the Jet-Dial portal with your user credentials. Click on the Account Manager link.
In Account Manager, navigate to Settings > Mailbox > and then click the pencil next to the mailbox you wish to edit
Type in the new mailbox Password (also referred to as Pin) 2 times as indicated below, and press the Save button.
When the disappears, it means the edit has been saved and you can now log in using the new password.