All user accounts have an email address associated with them. This is used for logging in and resetting passwords.
Schools with MIS synchronisation: first check the relevant employee details on your MIS and update the email address there. When MIS next synchronises overnight the email address will be updated for the account and the user will be able to log in using the updated email and their existing password.
Schools without MIS synchronisation: If a users email address changes, they will have to update the email address associated with their account. Please note that a single email address can only be attached to a single Classroom Monitor account. They can do this by accessing SETTINGS > Personal Settings > Change Email Address