Need help how to edit Samsung Firmware.. topic

Hello to all Users.

I try to find in all web site a guide that will help me to Larne how to edit A Offline Samsung Firmware ... I not want to Change big things I want to Add the Hebrew to the language . on the device have Hebrew if I run morelocale2 and Choose Hebrew but I want to edit the tar file and after that to flash it whit a Odin I and I want to add SU Super User to the app folder that will be on the rom after I Flash it whit the Odin I see it on different Rom that people Make I look every ware to find a guide but nobody make a guided like that All the experts here on the site also has not answered me about similar requests I hope that this time someone could help me .. Thank you and have a nice day