To remove files from your directory, you can connect to your directory with an FTP program (such as Fetch on Mac or FileZilla on Windows).  Highlight the file you want to delete, and choose the delete file option from the program menu.  If you are accessing your directory via Telnet, type the command:

rm   filename

where filename is the full name of the file you want to remove.

The selected file(s) will now be gone from your directory.