(1) The city council or governing body in cities which, according to the last federal census taken, have a population of seventy-five thousand (75,000) or over shall name by ordinance three (3) citizens of its respective cities as a board of civil service commissioners.
(2) The commissioners shall hold office as follows: One until the first Monday in April of the second year after his or her appointment;
(3) One until the first Monday in April of the fourth year after his or her appointment; and
(4) One until the first Monday in April of the sixth year after his or her appointment.