Installing aTV Flash (black) requires that you first jailbreak your 2nd Gen. Apple TV which can be done easily, and for free with Seas0nPass. Learn more about jailbreaking your Apple TV and installing aTV Flash (black) here.
First off, you will need a micro USB cable, access to a PC or Mac with the latest version of iTunes installed and the silver Apple TV remote control. Next, you will need to download the Windows or Mac version of Seas0nPass (free), one of the tools that can be used to jailbreak your Apple TV. 2b1af7f3a8