A cooperative may amend its articles of incorporation by complying with the following requirements: The proposed amendment shall be first approved by the board of trustees and shall then be submitted to a vote of the members at any annual or special meeting thereof, the notice of which shall set forth the proposed amendment. The proposed amendment, with such changes as the members shall choose to make therein, shall be deemed to be approved on the affirmative vote of not less than two thirds of those members voting thereon at such meeting; and, upon such approval by the members, articles of amendment shall be executed and acknowledged on behalf of the cooperative by its president or vice-president, and its corporate seal shall be affixed thereto and attested by its secretary. The articles of amendment shall recite in the caption that they are executed pursuant to this chapter and shall state: The name of the cooperative; the address of its principal office; the date of the filing of its articles of incorporation in the Office of the Secretary of State; and the amendment to its articles of incorporation. The president or vice-president executing such articles of amendment shall also make and annex thereto an affidavit stating that the provisions of this section were duly complied with. Such articles of amendment and affidavit shall be submitted to the Secretary of State for filing as provided in this chapter. A cooperative may, without amending its articles of incorporation, upon authorization of its board of trustees, change the location of its principal office by filing a certificate of change of principal office executed and acknowledged by its president or vice-president under its seal attested by its secretary in the Office of the Secretary of State and also in each county office in which its articles of incorporation or any prior certificate of change of principal office of such cooperative has been filed. Such cooperative shall also, within 30 days after the filing of such certificate of change of principal office in any county office, file therein certified copies of its articles of incorporation and all amendments thereto, if the same are not already on file therein.