Before you begin, you will need ADB and Fastboot setup correctly on your computer. Check out a guide on how to do this here.Download Super SU here.

Download TWRP here.

This process includes wiping everything from your device, so make sure you have a backup before you begin.

  • Plug your device into your computer VIA USB
  • Navigate to the CD Drive folder, double click on OnePlus_USB_Drivers_Setup.exe and install the drivers
  • Go to settings > About Phone > Tap Build number 7-8 times until you see “You are now a developer”
  • Go to Developer options and enable USB debugging, OEM unlocking and advanced reboot
  • Navigate to the folder where you saved the SuperSU and TWRP files, hold shift+right click and choose “open command window here”
  • Type adb devices into the command prompt and hit enter to see if your device is properly setup
  • Type adb reboot bootloader
  • Once your phone shows the bootloader screen, type fastboot devices
  • Type fastboot oem unlock and choose “yes”
  • After your phone reboots, enable USB debugging and OEM unlock in your settings again.
  • Going back to ADB, type adb reboot bootloader
  • Once you’re at the bootloader screen, type fastboot flash recovery TWRP.img with twrp being the name of the recovery file.
  • On your phone, use the volume keys to navigate to the recovery option, then use the power button to select
  • In TWRP go to advanced > ADB sideload > swipe to start sideload
  • In CMD type adb sideload SuperSU.zip with Super SU being the name of the zip file
  • On your phone, select reboot system

The phone will reboot a couple of times before launching into android and being fully rooted.

Check out the full thread on XDA here, if you have any questions.