update : used adb (thank you lunatic59 <3) , rooted it , flashed twrp custom recovery , but while the su binary was updating (i tried to update it with twrp automatically , from the su app , but it failed ) it got stuck on the 'updating' screen for like 10 minutes so i reseted the phone . long story short , it got bricked and i have to do all this all over again . i can still access custom recovery and download/odin mode , but what do i do? i dont wanna repeat the same mistake