S.D. Codified Laws § 47-21-8
A cooperative may amend its articles of incorporation by complying with the requirements of this section and § 47-21-9, provided, however, that a change of location of principal office may be effected in the manner set forth in § 47-21-76. The proposed amendment shall be presented to a meeting of the members, the notice of which shall set forth or have attached thereto the proposed amendment. If the proposed amendment, with any changes, is approved by the affirmative vote of not less than two-thirds of those members voting thereon at such meeting, articles of amendment shall be executed and acknowledged on behalf of the cooperative by its president or vice-president and its seal shall be affixed thereto and attested by its secretary.
SDCL 47-21-8