To change a user's display or username:1. Ask the the user to sign out of his or her Google for Work account.
3. From the Home page, click Users.
4. Click in the user list for the user you want to change and choose Rename user.
Click Rename User.
It can take up to 10 minutes for a new primary email address to be reflected throughout the system, 24 hours for domain and personal contact changes to take effect, and up to 3 days before the user can use Google Talk. See Impact of changing a username for a complete description.