Michigan Compiled Laws, Chapter 600. Revised Judicature Act of 1961 § 600.846

Sec. 846. In an action or proceeding pending in any other court of this state of which the probate court and the other court have concurrent jurisdiction, the judge of the other court, upon motion of a party and after a finding and order on the jurisdictional issue, may by order remove the action or proceeding to the probate court. If the action or proceeding is removed to the probate court, the judge of the other court shall forward to the probate court the original of all papers in the action or proceeding and thereafter proceedings shall not be had before the other court.