Doesn't work for me, copied the files to external sd, powered off, booted whilst keeping vol down, home and power pressed. It enters recovery mode and I select the top option (other option is restart) and it just sits there with a 'Downloading - Do not turn off target' message on the screen. Left it like that for 45 mins but nothing happens. Pulled the battery and it booted up fine again. Tried three times, to no avail.