The association may amend its articles of incorporation by a two-thirds vote of its shareholders at any regular shareholders’ meeting called for that purpose, or at a special meeting on 10 days’ notice to the shareholders: In either case the power to amend the articles of incorporation shall include the power to increase or diminish the amount of capital stock and the number and par value of shares, the par value, however, not to be reduced below that provided for in this act; Provided, however, that the amount of the capital stock shall not be diminished below the amount of paid up capital at the time the amendment is adopted, unless there be, at that time, in the treasury sufficient undivided profits over and above all legal debts or other like obligations to off-set the capital so returned to shareholders. Within 30 days after the adoption of an amendment to its articles of incorporation the association shall cause a certified copy of such amendment to be recorded in the office of the Secretary of State and of the recorder in the county where the principal place of business is located.