Please be aware that a user's email address cannot be changed, as it serves as the system's unique identifier.
In case the user has 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 Scheme Manager shall deactivate the user as seen here:
After this is done, a new user can be created with the new email address.