A corporation created under this chapter may amend its certificate of incorporation to change its corporate name, to increase or reduce the number of its directors or to change any other provision therein, provided, however, that no corporation shall amend its certificate of incorporation to embody therein any purpose, power or provision which would not be authorized if its original certificate, including such additional or changed purpose, power or provision, were offered for filing at the time a certificate under this section is offered. Such amendment may be accomplished by filing a certificate which shall be entitled and endorsed "CERTIFICATE OF AMENDMENT OF _____ ELECTRIC MEMBERSHIP CORPORATION" and state: The name of the corporation, and if it has been changed, the name under which it was originally incorporated; the date of filing the certificate of incorporation in each public office where filed; the purposes, powers or provisions, if any, to be amended or eliminated and the purposes, powers or provisions, if any, to be added or substituted. Such certificate shall be subscribed in the same manner as an original certificate of incorporation under this chapter by the president or a vice-president, by the secretary or the assistant secretary, who shall make and annex an affidavit stating that they have been authorized to execute and file such certificate by the votes cast in person or by proxy by a majority of the members of the corporation entitled to vote. Such certificate shall be filed in the same places as an original certificate of incorporation, and, thereupon, the amendment shall be deemed to have been effected.