In case the user had not yet created any data in CertifierOS he can be deleted by the Scheme Manager as seen here:
After this is done a new user can be created with the new email address.
In case the user has already created data in CertifierOS, e.g. adding producer(s), site(s), product(s), audit(s), the user shall be deactivated by the Scheme Manager as seen here:
After this is done a new user can be created with the new email address.