The City Council of said City is hereby authorized by ordinance to appoint and employ such boards and officers as may be necessary to administer, control, and make expenditures from such fund or funds; to appropriate by ordinance or resolution funds from which such benefits and expenses incidental to the administration thereof may be paid; to provide by ordinance the rate of contributions, if any, to such fund or funds to be required of employees and appointive officers to be eligible to benefits therefrom; to designate by ordinance a retirement age for City employees and appointive officers beyond which age such employees may be removed from office and permanently retired; to establish by ordinance conditions and regulations under which such City employees and appointive officers may or shall be removed from office and retired; to designate and establish by ordinance the sums which may be paid to such City employees as benefits and the conditions of payment thereof, and to make, amend or repeal such ordinances as may be convenient or necessary to create, manage, and operate a fund or funds for the payment to City employees and appointive officers of retirement, disability, and death benefits, or any one or more of them.