U must to reinstall manually an original firmware. It is simple, without writing all the guide in this post, this is the link with all the informations u need: http/forum.xda-developers.com/showthread.php?t=2365701
This procedure will delete all your personal data, in particular the "Part 5: Resetting and finishing". The guide says that this part is necessary, but i personally think it is not. In any case after Part 4 the phone will reboot, so check if all is right, if something crashes or isn't like it should, shutdown the phone and follow the Part 5. It is my suggestion.