1. In your Google Admin Console at admin.google.com
  2. Go to Users 
  3. In the Users list, find the user.
  4. Click the user’s name to open their account page.
  5. Click Groups.
  6. Click Add Add.
  7. Select the group you want.
  8. (Optional) Select more groups to add the user to.
  9. When you finish selecting groups, click Add.
  10. (Optional) To change a user’s role in a group:
    • Under Role, click the Down arrow Down Arrow.
    • Assign the new role.
    • Click Save.
  11. (Optional) To remove this user from a group, hover over the row for the group and click Remove.

    Or to remove the user from multiple groups, check those boxes, and click Remove.