This is a guide for all those who run into a circumstance that requires a complete return to stock. Most people who have windows can avoid this through the use of a toolkit like Wugs, but that still leaves those on Macs or Linux behind. Step 1: Make sure the fastboot drivers are installed & configured if your OS requires them. The easiest way is to use Koush's Universal drivers found here: Universal Driver Step 2: Make sure you have the fastboot files. You can get it from our mini-sdk here on the forums. Step 3: Download the factory image from Google Developer website. The latest builds are listed below: Nexus S Worldwide JZO54K Sprint JRO03R Galaxy Nexus GSM International JWR66Y US JWR66Y Verizon JDQ39 Sprint GA02 Nexus 7 (2012) Wifi LRX21P Mobile Data Enabled KTU84P Nexus 7(2013) Wifi LRX21P Mobile Data Enabled KTU84P Nexus 4 KTU84P Nexus 5 LRX21O Nexus 6 LRX21O Nexus 9 LRX21Q Nexus 10 LRX21P Once downloaded, extract the .tzg into the same folder you put the sdk files. Step 4: Make sure the device is connected to the computer while in fastboot mode. Different devices may require different commands to get into fastboot mode. Make sure the device is powered off and then use the following button commands: Nexus S - Vol Up + Power Galaxy Nexus - Vol Up + Vol Down + Power Nexus 7 - Vol Down + Power Nexus 4 - Vol Down + Power Nexus 5 - Vol Down + Power Nexus 10 - Vol Up + Vol Down + Power Nexus 9 - Looking to Confirm Nexus 6 - Vol Down + Power Step 5: Open up a command line terminal and navigate it to the location where the factory image and fastboot files are located. This can be done with the following command Windows users can take a shortcut by having the folder open with windows explorer and then using the combo of Shift + Ctrl + right click and then clicking on "Open session window here" Step 6: All commands are going to be executed through the fastboot binary. Windows: Mac: Linux For simplicity, I'm only going to progress using windows commands because it's simpler. First we want to make sure the computer sees the device. Use the command: This should return a device ID if it's recognized. If nothing is returned, it means your device is not connected in fastboot mode, or the drivers aren't installed/configured correctly. *Note* Steps 7 and/or 8 will wipe the device completely. So if you wish to back anything up, do it now. Step 7: If your bootloader is already unlocked, skip this step. If it is not, it has to be unlocked in order to flash anything. To do this, use the command: Use the Vol Up to go up to yes and then use the power key to select. The device should now be unlocked Step 8: We now want to wipe the device. Use the following commands in order: Step 9: We will now flash the bootloader. It is important that you do not disconnect the device or mess with it during this step or else you hard brick the device. Step 10: If using a phone or data enabled tablet, we will now flash the mobile radios. Some phones have more than one radio file. Flash the CDMA radio after the LTE radio. Step 11: We will now flash the system, boot, and recovery all in one shot with the following command: Alternatively, you could extract all the .img files in the zip file and flash them manually one at a time. This makes things really handy if you're using the factory image to act as an update rather than a complete return to stock. If trying to update using the factory image, extract the .img from the zip file into the same directory as your bootloader and radio img files and execute the following commands in order: If going for a complete back to stock using the manual flashing of the zip file, execute the following commands after the above 4: Step 12: The device now has been flash back to stock. Only one thing left to do is reboot. Your device will now reboot and should be completely back to stock as well as be unrooted.