Name changes are not terribly difficult but some hoop jumping is usually involved.
Under the old common law, a person could change their name simply by common and constant use of the new name in place of the old (and so long as they didn’t do it to defraud, etc.).
But we live in a sort of “official document” world today, and so name changes on our various I.D. cards and the like often require some sort of proof or affidavit or court order.  We can help you in Michigan, if you are working on a name change and find yourself confused a bit by the process, or want our professional help in making the name change.
A national group though, the National Center for Transgender Equality, has added a link about name change requirements with state by state postings on the laws involved, and you may want to look there for more info:  http://www.transequality.org/documents
In Michigan the ACLU filed a case regarding some challenges to Michigan last spring, and in November, although the state of Michigan asked that the suit be dismissed, the Court denied the request, and the case continues.  See more here:  http://www.clearinghouse.net/chDocs/public/PB-MI-0010-0001.pdf   and also here:  http://www.aclumich.org/article/judge-permits-aclu-lawsuit-challenging-michigans-id-policy-move-forward