Rename User’s Email Address in GSuite.
The ability to rename a user’s email address is now available in the administrator control panel.
How to access what’s new:
Go to ‘Organizations and users’ > Select the check box next to a user > Click ‘Rename user’ under the ‘More actions’ dropdown
Note: We advise you to read the help center documentation before performing this action
For more information:
http://www.google.com/support/a/bin/answer.py?answer=182084