Make sure to back-up your data before you start the upgrade as all data will be wipedin the process.
Make sure there is more than 40% battery.
Make sure there is at least 1.5GB free storage space on the phone or micro-SD card to
download the software installation package.
The whole process of installation will take some time, please do not do other operations
or power off your device during the installation process.
Download the software package which correlates your model (R9 Plus, R9 or F1s) 4GB RAM 64 GB memory
to the phone storageâ€™s (or SD card)root directory (ie not in any sub-folders).
Go to Files â€“ All files â€“ (click SD card if you have downloaded the package to SD card)
â€“ select the zip file â€“ Click Update now. (Figures below are shown as an example of SD card)