First step
Back up all the data on your phone, and back up all the backups, otherwise the data will be lost after the upgrade.
1. In the phone to find the desktop under the "Settings" open access, as shown in the following figure
2. Then find "More Settings" in the Open Settings interface, and then open the entry
3. Furthermore, we found the "system upgrade" open access, details as follows
4. When the mobile phone can be online, the mobile phone will automatically detect whether there is an update (preferably under the WiFi network)
(Updates will be prompted to download, download good, click "Verify and Install" can)
Method Two
1. Download the upgrade package at Vivo website Note to choose the installation package corresponding to your phone
2. Then the reverse installation files copied to your mobile phone in the "file management" in the "mobile phone U" root directory, after the copy is complete disconnect the phone and computer connection.
3. Then enter the mobile phone "file management"-"mobile phone U", find the installation package and then click it will pop up "start Upgrade" others do not need to operate.