If your phone can be updated to the higher Android version, after the update, you can downgrade its Android version at our service center. If your phone cannot be updated to the higher Android version, it cannot be downgraded to the lower Android version. Hope for your understanding.
For the detailed tutorial, please click: http://t.cn/EyQjTph
Thanks so much for your support. However, there are no international firmwares for the phones sold in Chinese Mainland. But don`t be upset, you can download & install Google Play Store to download apps & games for your daily usage.
Please be kindly informed that BL cannot be unlocked. We also suggest you not to try it. Vivo will not be responsible for any damage caused or changes that happen during or after unlocking Bootloader.
You can download the firmware for your phone on our official website. Select the model number of your phone, then click Download to download the firmware.
Power off your phone, then press and hold Power button and Volume up button simultaneously to enter Fastboot mode(For the phones with the 16:9 display screen, press and hold Powerbutton and Volume up button simultaneously until Vivo log appears to enter Recovery modedirectly). Then select Recovery mode by pressing Volume down button and enter it by pressing Power button.
Please be kindly informed that the firmware in different phones cannot be employed universally. We highly recommend not trying to install the firmware for other phones.
You can go to our service center to downgrade your phone. If you are meeting the unexpected problems in the current version, please feel free to contact us. We`d love to work with you to solve them.
If you can find Reboot or Reboot the system in Fastboot interface, select it by pressing Volume button and enter it by pressing Power button to exit this mode.
If you cannot find it, please don`t worry, you can long press the Power button and Volume down button simultaneously for 30s to reboot your phone to exit this mode(For the phones with 16:9 display screen, long press the Power button for 30 seconds to forcibly reboot your phone).
Please don`t worry, come to our service center near you and we will help you solve this issue.