S.D. Codified Laws § 58-35-14
A farm mutual insurer may, by a two-thirds vote of those present in person or, if authorized by the bylaws, by proxy, at any annual meeting, or at any special meeting of members called for that purpose, amend its articles of incorporation to extend its corporate existence or in any particular within the scope of this chapter, by causing amended articles to be filed in the same form and manner as required for original articles of incorporation. The amended articles of incorporation shall be signed only by the president and secretary of the corporation. Notice of the proposed amendment, or a summary of the changes to be effected thereby, shall be contained in the notice given of such annual or special meeting, and any number of amendments may be submitted to the members, and voted upon by them, at one meeting.
SDCL 58-35-14