1. Plug the micro-usb into the AppleTV2. Plug the power cord into the AppleTV3. iTunes will mount the device and you'll see it under Devices like a CD or iPhone.4. Select it and the Summary tab will offer one option - Restore5. Accept License Agreement and wait for the download and restore.Edit http://support.apple.com/kb/HT4367?viewlocale=en_US&locale=en_US explains it better cause it covers all gens. Gen1 was power before usb cable I think.