STEP 1: Install Android SDK
First and foremost, you will have to install the Android SDK Platform Tools on your PC. This is the official ADB and Fastboot binary provided by Google and is the only recommended one. So download it and then extract it to any convenient location on your PC. Doing so will give you the platform-tools folder, which will be used throughout this guide.
STEP 2: Download Pixel 6/Pro Stock Firmware
Next up, you will have to get hold of your device’s stock firmware. So download it from the below link (it is recommended to download the latest available firmware):
Firmware for Pixel 6 Oriole
Firmware for Pixel 6 Pro Raven
Once you have downloaded the firmware, extract it inside the platform-tools folder.
Likewise, consider renaming the radio file so that it becomes easier to type in the CMD window:
radio-oriole-xxxxxx-xxxxx-xxxxxx-x-xxxxxxx to radio.img
STEP 3: Boot Pixel 6/6Pro to Fastboot Mode
You will now have to boot your device to the Fastboot Mode. In most cases, as soon as the device is soft-bricked it automatically gets booted to Fastboot. However, if your device is stuck in a bootloop, then let it drain the battery so that the device gets powered off. Then connect your device to the charger and as soon as you do so, press and hold the Power and Volume Down keys. Your device will now be booted to Fastboot.
STEP 4: Flash Pixel 6/Pro radio via Fastboot Commands
To begin with, connect your device to the PC via USB cable. Make sure it is booted to Fastboot Mode
Then head over to the platform-tools folder, type in CMD in the address bar, and hit Enter. This will launch the Command Prompt.
Next up, flash the radio file and reboot using the below commands:
fastboot flash radio radio.img
Εννοείται όλα αυτά με δικό σας ρίσκο.