Press and hold Home and Power button for more than 10 seconds. Your iPhone should turn off, and turn back on again. Continue hold ONLY the Home button until the Apple logo appears, this should initiate the recover mode, which will come to that screen which shows the first time you turn on your iPhone before activation. Connect it to iTunes, let it detect it as a new iPhone, and close iTunes. Remember to also kill iTunesHelper app/program as well. Then run iLiberty+.