How to unlock or relock the bootloader of the Nexus 4 E960

Unlocking your phone’s bootloader is one of the first few steps to flashing custom ROMs. Some phones’ bootloaders are almost impenetrable, while others are very easy to unlock. Whatever the case, software development can only happen when a device’s bootloader can be unlocked. This why many developers burn the midnight oil to unlock the secrets to a phone’s bootloader. Thanks to Google and the spirit of Open Source, Nexus devices’ bootloaders, including the popular LG Nexus 4 E960, are not very difficult to unlock.
While there are plenty of toolkits ready to do most of the work for you, it never hurts to learn how to do things manually. XDA Developers member TheDarkDefender shows how simple unlocking your Nexus 4′s bootloader really is. Remember to make a backup before you proceed to the steps below.
This guide shows you how to unlock or relock the bootloader of the Nexus 4 E960.

Warning

• The instructions in this guide are intended for use with the LG Nexus 4, model number E960. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• LG Nexus 4 E960
• A Windows PC
• Download Fastboot (Fastboot.zip, 404.46 kB).
• Make sure your device’s battery still has at least 70% power. You don’t want the device to shut down in the middle of the procedure.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.

Instructions

1. Turn your phone off.
2. Boot your phone into Fastboot Mode by holding down the Volume Up, Volume Down, and Power buttons until your screen turns on.
3. Connect your phone to your computer via USB cable. If this is the first time you have connected your phone to the computer, your phone’s drivers will automatically install. Wait until the drivers have completely installed before proceeding to the next step.
4. On your PC, open a command prompt with Administrator privileges.
5. At the command prompt, navigate to the directory or folder where your Fastboot binary has been saved.
   • For example: C:\Windows\Program Files\Android SDK\Platform Tools
6. Check if your computer recognizes your phone. Your phone’s serial number should appear on the command prompt window after you enter the following commands:
   • fastboot devices
7. To start unlocking your bootloader, enter the command below.  Or, if relocking your phone, use fastboot oem lock instead.
   • fastboot oem unlock
8. On your phone, confirm that you want to unlock your device by selecting Yes at the dialog.   Read and understand the warning displayed on your phone’s screen.  Your phone will reboot after this process.

Great job! Your LG Nexus 4 E960′s bootloader has been successfully unlocked and re-locked