Wie kann ich den Namen einer PDF Datei ändern?

IF the PDF is locked, you cannot unless you know the password to unlock the file.

Otherwise, you can either do a "Save as..." to create a new file with the new name, OR in your operating system, click on the title, pause, then click again, and the name should be highlighted to rename, OR right-click on the file in your OS and select "Rename." The title will be highlighted to rename it at that point.

Please let us know if this helps.