>See http://msdn.microsoft.com/en-us/library/bb522469.aspx
>
>and there
>To move a data file or log file to a new location, specify the current logical file name in the NAME clause and specify the new path and operating system file name in the FILENAME clause. For example:
>
>Copy
> MODIFY FILE ( NAME = logical_file_name, FILENAME = ' new_path/os_file_name ' )
>When you move a full-text catalog, specify only the new path in the FILENAME clause. Do not specify the operating-system file name.
>
>For more information, see Moving Database Files.

I got confused at first because I thought about a FileGroup syntax while I had to search for a File syntax. I posted Message #1505455 while you were writing this one.