The municipal judges shall be elected on the first Tuesday after the first Monday in November, 1958, and on the first Tuesday after the first Monday of November every fourth year thereafter by the electorate of the city in which the court is located. The auditor of the county concerned shall designate by number each position to be filled in the municipal court, and each candidate at the time of the filing of his or her declaration of candidacy shall designate by number so assigned the position for which he or she is a candidate, and the name of such candidate shall appear on the ballot only for such position. The name of the person who receives the greatest number of votes and of the person who receives the next greatest number of votes at the primary for a single nonpartisan position shall appear on the general election ballot under the designation therefor. Elections for municipal judge shall be nonpartisan. They shall hold office for a term of four years and until their successors are elected and qualified. The term of office shall start on the second Monday in January following such election. Any vacancy in the municipal court due to a death, disability or resignation of a municipal court judge shall be filled by the mayor, to serve out the unexpired term. Such appointment shall be subject to confirmation by the legislative body of the city.