• Ensure that the device is on the latest Android 10 firmware.
• Ensure that the device has at least 60% battery remaining.
• First: if you use anything else than a PIN code to unlock your phone, change it now. Last TWRP image for Android 10 asks for a data decryption password. It will be easier if it’s a PIN code. Go to Settings > System > Security and change your screen locking choice by a PIN code.
• Make sure your computer has adb and fastboot. Setup instructions can be found here.

The OnePlus 6T uses the newer AB partition scheme first introduced on the Pixel 1. As such there is no recovery partition. Instead, the recovery is part of the boot image. You will temporarily boot TWRP to perform and later perform a more permanent TWRP installation.

First: if you use anything else than a PIN code to unlock your phone, change it now. Last TWRP image for Android 10 asks for a data decryption password. It will be easier if it’s a PIN code. Go to Settings > System > Security and change your screen locking choice by a PIN code.

1. Prepare phone:
   1. Enable Developer options: Settings > System > About. Tap repeatedly on “build number”
   2. Go back to System, then go to developer options.
   3. Enable USB debugging
   4. Enable bootloader OEM unlocking, if present. Make sure that from now on, OEM unlocking option is enabled before you reboot. Sometimes, it might get disabled itself.
   5. Enable advanced reboot options.
2. Connect the device to your PC via USB.
3. Download all the files:
   1. place Magisk & TWRP installer zip on Device Internal Memory
   2. place TWRP img on your PC
4. Boot into fastboot bootloader mode. Open a terminal window, and type:

   adb reboot bootloader

   You can also achieve this via a key combination: Enter-fastboot-recovery.

5. Temporarily boot into TWRP:

   fastboot boot twrp-img-name.img

   Wait for TWRP to start. Decrypt your data thanks to your PIN code. Swipe to allow system modifications.

6. On your computer, execute adb devices (it should list your device)
7. Now in TWRP, tap on Install and browse to the zip and install TWRP (the zip will probably be in /sdcard/Downloads).
8. TWRP will now be installed to both slots
9. PS: DO NOT BOOT IN OS JUST YET & CONTINUE TO THE ROOTING POST

1. Boot into TWRP Recovery
2. If you want to stay systemless continue without swiping right else Swipe and enable modifications.
3. Select your preferred Language, Tap “Never show this screen on boot again,” and Swipe allow modification.
4. Navigate to Install and select Magisk to root.
5. Swipe to confirm the flash
6. Reboot System

Keep in mind that the first boot after wiping the phone may take longer than usual, as the phone will need to rebuild the dalvik cache and initialize other first boot and might reboot a few times.