The board of trustees of any such school as is discontinued, as provided in Section 37-27-83, is further authorized with the approval of the board of supervisors to reconvey to the original grantors thereof, or their heirs, any lands which may have been donated to the trustees of such school for school purposes, except that part of the same, to be designated by the board of trustees, on which the school buildings are located. The deeds of conveyance shall be executed as provided in Section 37-27-83.