find the duplicates between two users

  delete  FROM tbl_Users

WHERE User_ID = 'cgius'

  AND Site_Location IN (

SELECT b.Site_Location

    FROM tbl_Users a

    JOIN tbl_Users b

      ON a.Site_Location = b.Site_Location

    WHERE a.User_ID = 'cccook'

      AND b.User_ID = 'cgius'

  )