Conn. Gen. Stat. § 33-211: Changes in certificate of incorporation.

Any such corporation may at any time amend its certificate of incorporation by a three-fourths vote of its members present and voting at a meeting of the corporation called to consider such amendment or, if the vote upon such amendment is by mail, by a three-fourths vote of those members who have returned ballots, and shall cause a certificate, attested by its president and secretary, setting forth the fact that such vote has been passed and stating the subject matter of such amendment, to be filed, approved and recorded in the same manner as the original certificate of incorporation.