Get Back Belongings That Are Forcibly Being Kept From Me

So my partner and I broke up after living together for about 11 months. I came back to the house the day after we broke up to collect my stuff and be done, and within that time period she had changed the locks and called the cops on me and almost got me arrested. The police on scene stated that if I wanted to get my stuff back and she wouldn’t help me I would have to take her to court over it, that they wouldn’t let me in the house either to get my stuff. I tried to be civil at least and reach out to her to get my stuff back because all I want are my memorabilia, picture books of my family and other similar shit that she has no reason to keep, and I’m seriously worried that she might throw out. My question is how would I even go about trying to take her to court over this? The police on scene were no help answering questions, and when I tried to look this up on Google all I got were landlord laws, for reference I’m in Michigan, I’m just at a bit of a loss and could use any guidance or resources