California Code, Financial Code - FIN § 5701

At any regular or special meeting called to consider the conversion of an association into a federal association, in the case of a stock association, the stockholders entitled to vote and any members entitled to vote, by an affirmative majority of the votes cast in person or by proxy; and in the case of a mutual association the members, by action on a proposal approved by the members, may resolve to convert the association into a federal association.