Finally, Oppo started rolling out Android Marshmallow Update for OPPO R9 Plus, R9, and F1s.
(Make sure to backup your data before you start the upgrade as all data will be wiped in the process.)
1. Download the software package which correlates your model (R9 Plus, R9 or F1s) to the phone storage’s (or SD card) root directory (ie not in any sub-folders).
2. Go to Files – All files – (click SD card if you have downloaded the package to SD card) – select the zip file – Click Update now. (Figures below are shown as an example of SD card).
3. Your device will then reboot and display the progress of upgrade (see figure below), which will take some time. Please do not do other operations or power off your device during the process.
4. After the progress bar is complete, the phone will reboot and remain on the OPPO logo for 3 to 5 minutes. Please do not power off the device as this is normal.
5. Once the phone is fully booted up, the standard start-up guide will show up to set up the language, region, and Wi-Fi. Upon completion of the guide, please check Settings – Dual SIM and mobile network – Preferred network type, and make sure you have selected 4G/3G/2G (Auto) as Preferred network type.
6. And by now, congratulations, you have successfully upgraded the software.