Oct 03, 2017 · Turn your Pixel device Off. Press and hold the Power key. When the Google logo appears, let go of Power key but at the same time press and hold Volume Down key. When the phone restarts and displays Safe Mode message, release the Volume Down key.
Nov 04, 2018 · This will again boot back to fastboot mode but this time you will see the device state as unlocked. So it means you have successfully unlocked the bootloader on your Pixel 3 and Pixel 3 XL. Press the power button and if any warning comes up then again press the power button to boot the device into the system.