To rename a user:

  1. Have the user log out of his or her Google account.
     
  2. Sign in to the Google administrator control panel.

    The URL is https://www.google.com/a/cpanel/primary-domain-name, where primary-domain-name is the domain name you used to sign up with Google.
     
  3. Click the Organization & users tab.
     
  4. If you created an organizational structure, select the organizational unit to which the user belongs.
     
  5. Select the check box next to the user's name and select More actions > Rename user, or click the row to open the user information page for that user and click the Rename user link.
     
  6. Enter the new name for the user.

    You can change the user's display name (First name and Last name) as well as his or herPrimary email address. If your Google Apps account includes multiple domains, you can change the domain name by selecting it from the drop-down list.
     
  7. 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 renaming a user for a complete description.