It is probably no different than if you evicted a roommate. You will need to set his property aside as outlined in the divorce decree. You can send him a certified letter, return receipt requested, that his property as outlined in the divorce decree (list the property) will be considered abandoned if he doesn't remove all of it from your home before a partcular date. Usually it's 30 days, you may want to give more or look up MI law to make sure you're within the time frame MI law requires.
Along with that, give him specific times and dates you will be available (give many) for him to pick up property. Make sure these are times and days he usually does not work. Be sure to leave your phone number in case he wants to call and make certain arrangements for a specific day. If he does not comply by the date you gave him to comply, make sure he knows you will dispose of all the property and will not be liable for it, for it's value, or for reimbursement to him.
A link to MI law, where you might be able to find out the legal procedure of all this:
http://www.michiganlegislature.org/mileg.asp?page=chapterIndex
Just make sure you do everything by mail, return receipt requested, keep copies of everything you send, keep your end of the bargain. If he doesn't comply with the law, too bad for him.
