Good question. If there has been a judgment of possession but not set date for the actual eviction then most likely the changing of the locks by the landlord was a bit premature in that in most situations where there has been a judgment for possession the court set a date when the holdover tenant must be out of the premises that were the subject of the lawsuit.From what you have written, it appears that the changing of the locks by the landlord was improper and was a clear example of improper self help by the landlord. If the judgment of possession had a set date for the tenant to be out of the premises and the landlord changed the locks before that date, then the action by the landlord was improper.