Philip, left click on the white icon in your icon tray and go to Apache > httpd.conf In that file, search for the numbers 80. There will be two references listings one for "Listen 80" and another for "ServerName localhost:80" simply change them both to a custom port and save the file. Then restart apache. Don't forget you will now need to access your server using http://localhost:8080 presuming you set your new port to 8080.

Hope this helps.