In all cities of the first class located in counties having a population of more than sixty thousand (60,000) and not more than one hundred thousand (100,000), the judge of the municipal court shall be appointed by the judges of the district court of the district in which said city is located in each odd-numbered year, commencing in 1971, to take office on the third Tuesday in April in such year, or as soon thereafter as appointed and hold the same until his or her successor shall have been appointed and shall have qualified.