California Code, Financial Code - FIN § 5756

Any amendment to a merger or consolidation agreement may be adopted, and the agreement so amended may be approved at the meeting of the stockholders or members of any of the associations or by written consent of the stockholders or members, in the same manner and by the same vote as the original agreement.  If the agreement so amended is approved at a meeting or by written consent by the stockholders or members and by the board of directors of each of the associations by the vote or written consent required for approval of the original agreement, the agreement so amended shall be signed and acknowledged and shall have certified therewith the approval of the directors and of the stockholders or members in the same manner as provided for in the original agreement, and shall then constitute the merging or consolidating agreement.