1) Edit /etc/pure-ftpd.conf and look for the following line:
Where is a publically routable IP. The default example, 127.0.0.1, will cause the socket to bind locally but then this connection won’t serve externally. is the new port you wish to put the service on.
2) If necessary, add the new FTP port to your server’s firewall
3) Edit /etc/chkserv.d/ftpd and change the port, which is the first comma-separated entry to the right of ‘=’ on the line in the file, to match the port you put the service on.
/etc/init.d/cpanel restart (restarts tailwatchd/chkservd)