Any domestic fraternal benefit society may be converted and licensed as a mutual life insurance company by compliance with all the requirements of the insurance laws of this state for mutual life insurance companies. A plan of conversion shall be prepared in writing by the board of directors setting forth in full the terms and conditions of conversion. The affirmative vote of two-thirds of all members of the supreme governing body at a regular or special meeting shall be necessary for the approval of such plan, or if the society is organized under the direct election method pursuant to RCW 48.36A.030(1)(b), the plan of conversion shall be submitted by mail to the benefit members or the plan may be published in the official publication authorized by RCW 48.36A.070(2)(a). The affirmative vote of two-thirds of the benefit members voting thereon shall be necessary for the approval of the plan. No conversion shall take effect unless and until approved by the commissioner who may give approval if the commissioner finds that the proposed change is in conformity with the requirements of law and not prejudicial to the certificate holders of the society.