OnePlus has just released the latest update for its flagship smartphone, the OnePlus 3T and it has got latest Oxygen OS 4.0.0 update which is based on v7.0 Android Nougat. This is an official build but OnePlus hasnt started rolling it out so you will not be able to get OTA update for this build but you can download and flash this build using below guide to get latest Android flavor on your OnePlus 3T.
This is an beta update and it might have some bugs, but several of our sources has told us that with this update you can use device for daily driver.
Before we begin with make sure your device is atleast 50 percent charged and it is advisable to make backup of your device, however this update will not wipe your data but we suggest you to backup.
First of all download this update file from HERE, its an official update so dont worry.
Download Android ADB, extract it and keep this and downloaded updated file in same folder.
Now its time to make yours device ready, first of all navigate to Setting-> About Phone and tap on build number seven times to enable Developers Options, now navigate to Settings -> Developers Options and Enable USB Debugging.
Turn of your device
Enter into recovery mode by pressing Volume Down and Power button and then select Install From ADB
Connect it with your PC
Navigate to folder where you have extracted Android ADB Platform Tools and open CMD with administrator privilege, for this simply press and hold Shift button and right click anywhere inside the folder, you will see option says Open Command Prompt
First we have to make sure your device is connected, for this type adb devices into the command prompt, and you should see your device listed there with sideload written next to it, if your device is not listed then you have to give few commands as well, first type adb kill-server and then adb start-server, if still your device is not listed then unplug and plug your device again.
Once your device is listed, type adb sideload FileName.zip
Wait for sometime and once it finishes flashing files, go back to your recovery and clear cache and reboot your device.
Disclaimer :- This guide is tested and it is working at our end, but we are not responsible if anything goes wrong with you or your device.