At such time as the Municipality shall become a City, the Council shall by ordinance provide for and establish a Civil Service Commission and Civil Service System or equivalent personnel system to provide for the appointment and promotion of persons in the service of the Municipality according to merit and fitness to be determined, as far as practicable, by competitive examinations, and shall determine which employees of the Municipality shall be within the classified service and which shall be within the unclassified service or similar categories of service. Such ordinance shall provide that all persons who have been continuously employed in the service of the Municipality in the same or similar position included in the classified service or equivalent category of service for at least ninety (90) days preceding the effective date of the ordinance, shall retain their position without examination until discharged, reduced, promoted, or transferred in accordance with the rules and regulations of the Civil Service Commission or other body authorized by ordinance to adopt such rules and regulations. The provisions of the laws of Ohio regarding selection, promotion, and removal shall be applicable except as otherwise provided by ordinance.