How Do I Turn An 'Unregistered' Entry Into A Registered User? Follow
Admins cannot do this directly. Please follow either of the 2 methods bellow to resolve.
1) The user themselves creates a login, applies for membership of your site and you merge the two records.
2) You add (or remove, save and re-insert) their email address in the record that you already have; that sends an invite to them to turn that record into their own login. Once they have done that you can add roles to that user