You can find a lawyer in any given Michigan county who handles eviction proceedings. Given your distance, you may wish to call the District Court in the county where the property is situated, and ask the clerk if they can give you the names of some of the attorneys who are handling evictions on this week's docket, then contact those attorneys. (I can't promise that a clerk would be that helpful, but I've known many who would.)

You will need to have somebody with knowledge of the case appear in court as a witness. Since your uncle isn't available, you may have to execute a power of attorney to somebody else up here in Michigan to appear in court on your behalf. (Unless you choose to travel back and appear yourselves.)

It seems that there is a possibility that your uncle(-in-law) has been collecting rent, and just not telling you. It is important to discuss that possibility with the lawyer, as it will affect the type of notice that must be given to the tenant. (A 7-day notice for non-payment of rent, or a 30-day notice to terminate tenancy.)