Arabic language for HTC 1 M8

A Syrian guy bought HTC 1 M8, it still new, so I don't know what's the android version but it's the default one. He came to me for help. He wants the whole system to be translated to Arabic, and that language isn't available. According to this video , if we just force stopped customization settings provider, it will allow us to select the Arabic language from settings. Is It correct? Is it that simple? Don't I need to root it and stuff? What happens if he restarts the device?