Mich. Comp. Laws § 168.284

Sec. 284. A person who is certified by the state central committee of a party as nominated for membership on the state board of education, the board of regents of the university of Michigan, the board of trustees of Michigan state university, or the board of governors of Wayne state university may withdraw by filing a written notice of withdrawal with the secretary of state or his or her duly authorized agent and a copy with the chairperson and the secretary of the state central committee of the party not later than 4 p.m., eastern standard time, of the fourth business day following the conclusion of the convention at which the person was nominated.