If you are using the webclient for staffing, you can change your password via the Preferences page. If you are using a third party chat client, there should be a change password feature that you can use to change the password on your LibraryH3lp account.
Administrators can change passwords for any of their users from the users management page in the admin dashboard.
If you've forgotten or misplaced your password, you can use the password reset feature on the login page, assuming your user has an email address configured. You can also e-mail us your username and we'll reset your password for you, or we can set an email address for your user so that you can use the automated password reset features.