(1) The district court shall commence to function in the forty-fifth-a and forty-fifth-b districts as of January 1, 1975 and as of that date all municipal courts within the district shall be abolished.

    (2) Effective January 1, 1975, the elected incumbent attorney municipal judge of the city of Berkley shall become the judge of the district court within the forty-fifth-a district and shall serve as a district judge until 12 noon of January 1 of the odd numbered year next following the date on which his term as municipal judge would normally have expired. In seeking election to the district court after January 1, 1975, the municipal judge becoming a judge of the district court pursuant to this subsection may file an affidavit of candidacy in like manner as other incumbent judges of the district court and shall be entitled to designation on the ballot as a judge of the district court.

    (3) Effective January 1, 1975, the elected incumbent attorney municipal judge and associate municipal judge of the city of Oak Park shall become judges of the district court within the forty-fifth-b district and each shall serve as a district judge until 12 noon of January 1 of the odd numbered year next following the date on which his term as municipal judge would normally have expired. In seeking election to the district court after January 1, 1975, a municipal or associate municipal judge becoming a judge of the district court pursuant to this subsection may file an affidavit of candidacy in like manner as other incumbent judges of the district court and shall be entitled to designation on the ballot as a judge of the district court.