Kim, you have to Airplay it from the either the Livestream app or just from the Disunplugged.com page. I am doing that at the moment. There is no way to manually put in an HLS stream into an AppleTV that has not been jailbroken.
You can stream directly from livestream using an Android appliance
Of you have an iPod or iPad with an Apple TV and you steam through that device you can AirPlay the show onto the TV. Therefore watching the show live on TV. I've done this several times with movies and other things. Double tap the home button slide to the left and tap the air play button. Turn on Apple TV AirPlay and it should work no problem.