Double click 'Terminal' in the left sidebar to open your Mac's Terminal. Type the port number and click on Next button to continue. Click Start menu, type cmd command in Search area. As far as I know, you cannot enable Telnet via Mac OS X's GUI, so you would have had to either use a 3rd-party utility or manually enable Telnet access. Open port on mac MacPass is free, open source software licensed under the GPLv3.
