1.Login to your G Suite admin account here https://admin.google.com
2. From the Admin Dashboard, go to Users.
3. On the Users page, please click on Rename (the pencil icon) next to the user whose Display Name or Username you would like to change.
4. Change either of the options in the next window:
First name and Last name – This changes the user’s default Display Name.
Primary Email address – This changes the user’s log in name and primary email address.
Click Rename and you’re done!