There is one way for OnePlus update:
If you want to install an OnePlus update using recovery – download the official update, reboot your phone or tablet into recovery mode and click “Install update from SD card”.
If your device does not support automatic updating, you need to install an alternative firmware (ROM).
System update individually for each Android smartphone or tablet. Therefore, there is no universal software or software for updating Android.
You can update Android using the system update tool, download the update for your device in the list and save it to your SD card or internal memory.
In the process of updating Android you may need advanced system settings.
After updating the firmware, you may need instructions on how to get root access to your device.Read more