Notwithstanding anything to the contrary in this title any municipality in this state having a population, according to the 1940 official federal census exceeding 8,000, but not exceeding 9,600, and operating under "code charter" as defined by chapter 3 of this title, may as hereinafter set forth, change its form of government to a plan of government hereby designated as the "council form" in order to place in the council of any municipality, operating under such form, full and complete executive and legislative powers over its entire municipal affairs.