Whenever the qualified voters of any incorporated city desiring to adopt a commission form of government so declare their desire by filing with the governing body of that city a petition having the signatures of one-fourth of the qualified voters voting at the last city election, the governing body shall cause 15 qualified electors to be elected at the next primary or general municipal election or primary or general state election to frame a charter which provides for a commission form of government for the city. The persons elected must:
1. Have been residents of the city for at least 2 years preceding their election; and
2. Be registered to vote in the city.