This does fit in with the "factory image" thread where you posted it, Rain, but I think it still should have a thread in its own right, so I've used your post as the OP for a new thread here in GNex ATR.
From that linked site, the steps:
1. Download the Android 4.0.2 factory images to your PC. [Download
2. Unzip the file and its contents into your SDK/Tools folder (wherever your adb.exe and fastboot.exe files are).
*Make sure they are not in their own folder, but have all been extracted to Tools.
3. From within your Tools folder, open a command prompt (SHIFT + right click – “open command prompt here”):
4. Type the following commands, allowing each to finish before moving onto the next:
adb reboot bootloader
fastboot flash bootloader bootloader-toro-primekk15.img
fastboot flash radio radio-toro-i515.ek02.img
fastboot flash radio-cdma radio-cdma-toro-i515.ek05.img
fastboot -w update image-mysid-icl53f.zip
fastboot oem lock
5. Reboot your phone by highlighting “Start” and pressing the lock switch.
6. It really is as simple as that. Your phone is now back to a 100% stock, unrooted and locked state.