These are the instructions to unlock the bootloader of Google Nexus 6P using the adb and fastboot tools on Windows Computer.
Caution: Unlocking the bootloader may void your device warranty, and will erase the user data including the contacts, images, apps, etc.
The above command will help you to verify that your device is successfully connected to the computer or not.
The Above command will reboot your device into the normal mode.
Thats All. Your device bootloader is successfully unlocked. Now, you can flash any custom recovery on your device without having any issue.
[*] Caution: Unlocking the Bootloader will erase your personal data, so take a backup of your important data before following the above tutorial.
[*] Unlocking the bootloader will also void the device warranty. So, Beware.
[*] How to Root Google Nexus 6P: If you wish to root your Google Nexus 6P smartphone then follow How to root Google Nexus 6P tutorial.
[*] Google Nexus Pixel Stock Firmware: If you are looking for the original firmware for your device, then head over to Download Google Nexus Pixel Stock Firmware page.
[*] Google Nexus Pixel USB Driver: If you are looking for the original USB Driver for your device, then head over to Download Google Nexus Pixel USB Driver page.