Itunes is not automatically starting the restore process, instead is asking to restore and update to the 5.3 Firm…
Hold SHIFT and simultaniously click ‘Restore’, then navigate to C:\Users<name>\My Documents\Seas0nPass\AppleTV2,1_<AppleTVversion>_10B809_SP_Restore.ipsw
Hope this helps, message me if you have any problems.
//Matt