Username policy in Security console

Summary

Change username policy for total population

Content

Dear all,

we need to revise the rule for usernames because of the out-of-the-box-integration with recruitment. So far we use FirstName/LastName as username. Now we want to change to the email address as username. If I change the rule in the security console, it applies only to employees that are entered after the change. Existing employees keep their current username. However I need to change the username for all employees.

Does anyone know how to do that?