How to update vivo system os via sd card

 This step only support new OS operating system
1.Turn off your phone

2.Press Hold Power button with Volume Up button Together then (Choose Recovery Mode)
   by Press Volume Down Button and confirm by Press Power Button

3.Choose Install Update by Pressing Volume Down Button then confirm by Press Power Button

4.Phone will show directory root folder then find where your put the file update

5.Select your file update then Install by Agree confirmation. That's it ! Good Luck