ONE UI 4.0

[san990]

EXPLANATORY NOTE .... PERSONALLY I AM NOT TELLING PEOPLE TO DO IT ONLY IS THAT I HAVE AN S 21 ULTRA FROM ATT AND IF I CHANGE THE SOFTWARE TO U1 AND THE SOFTWARE IS UPDATING AS THE GLOBAL IS DOING IT UNLOCKED .... I JUST GOT THE RIGHT SOFTWARE AND THE RIGHT ODIN. 

[user_ams007]

I would not recommend that for users who are not familiar with that process, I can brick your phone and void the warranty,