From your regular HomeBase view, right click on the client file and choose Rename and give it an appropriate file name.   The file name will end in .19i so no need to include the tax year in the file name itself.

(ProSeries will automatically assign the first 4 letters of the last name and the last 4 of the taxpayer SSN, for a new client file.... so you may want to use that same naming system for all files)