[STOCK] How to Unroot Nexus or Return to Stock or Flash a Factory Image

Google Nexus devices (only the latest devices) are the first in the world (if not flashed with a custom ROM) to get the Latest Android versions. This guide explains how to flash a stock Factory image to a Nexus device. Flashing a stock Nexus image is helpful to make a Nexus device unrooted if the it is rooted, to return back to stock Google image (if you have installed a custom ROM) so that you can get the early taste of the newest sweetest android etc.

REQUIRED DOWNLOADS AND GUIDES TO INSTALL NEXUS FACTORY IMAGES:

This will delete all your data on your phone. IGNORE IF YOU DON’T WANT TO OR IF YOU HAVE ALREADY DONE THIS. You may consider complete backup of your phone data or take a NANDROID backup of the current ROM.
– How to backup all data on your Android Device.
– how to take NANDROID backup using TWRP recovery.

STEP by STEP GUIDE TO FLASH A FACTORY IMAGE ON A NEXUS DEVICE:

If you don’t have an unlocked bootloader on your Nexus device then follow the below link to get it done:
Unlocking the Bootloader on any Android:

FLASHING A NEXUS FACTORY IMAGE:

Unlock the bootloader and download the factory Nexus images to be installed.

To make it understandable I have downloaded the factory image for my Nexus 4:
verion: 4.4.4 (KTU84P)

NOTE:
The zip file comes in a package which might have similar to the following files:
– bootloader image: bootloader-mako-makoz30d.img
– radio image: radio-mako-m9615a-cefwmazm-2.0.1701.03.img
– The actual Android system image: image-occam-ktu84p.zip
– scripts for different platforms like Windows and linux that will flash all of the images by itself to your device.

After completing the above steps there are are although several methods that you can follow to flash a factory image to your Nexus device, but here I am going to show you the easiest method to do it.

Power off your phone and boot into fastboot by pressing and holding Power Button + Volume Down at the same time.
And then connect your phone to the PC using a USB cable.

Run the flash-all.bat by double click on the script file.
For linux users you have to run the flash-all.sh script file.

Wait for the script till it flashes everything.

Alternatively you can flash them manually with the following commands:

fastboot flash bootloader bootloader.img
fastboot flash radio radio.img
fastboot flash system system.img
fastboot flash userdata userdata.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img
fastboot erase cache
fastboot flash cache cache.img

After everything finished, select “Recovery” using the volume buttons. When a small dead Android appears, press Power Button + Volume UP.
Select “Wipe data/factory data reset”

This will delete all your data on your phone. IGNORE IF YOU DON’T WANT TO OR IF YOU HAVE ALREADY DONE THIS. You may consider complete backup of your phone data or take a NANDROID backup of the current ROM.
– How to backup all data on your Android Device.
– how to take NANDROID backup using TWRP recovery.

Now reboot your phone and enjoy a brand new (atleast from software perspective) stock Android version.