You have a tenant that walked out with 9 more months on their lease How can you report this to the credit bureau?

You would have to become a contributing member of the credit bureau in question to contribute information on an individual. This is not always possible (legally), nor cost-worthy. However, if you wanted to sue your former tenant in small claims or civil court; if you prevail and are granted a judgment, THAT legal item would get picked up and eventually show on the person's credit report.