(1) Any insurer transacting business under subdivisions (1) (disability) or (3) (life) of section 6406, or under both such subdivisions, may, at its option, convert itself without reincorporation into a mutual insurance company transacting the corresponding kind or kinds of business, and become subject to the provisions of section 5408 through 5430 (provisions applicable to domestic mutual life and disability insurers) and the applicable portions of sections 408 (capital, surplus, assets required) and 412 (deposit requirement), upon meeting the surplus and other requirements of said sections. Any insurer transacting only the kinds of business specified in subdivisions (1) (disability) and/or (2) (loss of position) of section 6406, may, at its option, convert itself without reincorporation into a mutual company and continue to transact the said kind or kinds of business, and become subject in all other respects to the provisions of chapter 58 (domestic general mutual insurers) upon meeting the requirements of said chapter.

  (2) The board of directors, trustees, or managers, shall adopt, in the manner provided by law, such amendments to the articles of incorporation and the bylaws of the insurer as shall be necessary to make the same conform to the articles of incorporation and bylaws of a mutual insurance company, as above limited. Upon approval by the commissioner of such amendments, and the filing of a certified copy of the amendments to the articles of incorporation with the county clerk of the county in which the principal office of the insurer is located, such insurer shall be subject to the provisions and entitled to the benefits of the sections or chapter above designated, as the case may be.

  (3) Such conversion into a mutual insurance company shall not affect the rights or obligations of the insurer or its members on any contract theretofore made.