Android 5.1 Lollipop for the Nexus 4 has started rolling out a few days ago, bumping up the smartphone's Android build from LRX22C to LMY470.
This makes the Nexus 4 one of the last few Nexus devices to receive the highly anticipated major maintenance upgrade from Google, which consists of a relatively large 174 MB of files meant to address major bugs and problems found in earlier versions of Android Lollipop.
But while some users have started receiving the over-the-air (OTA) update for Android 5.1, plenty of others are still waiting for the update to arrive on their phones. That's normal, since it usually takes several days for the update to reach all devices. However, if you cannot wait any longer and would like to update your Nexus 4 now, you can flash the factory image officially released by Google on the Android developers' website.
There are several things to remember when using this method. First, the factory image will install a stock Android 5.1 on your Nexus 4 and will wipe out all files and settings you have on your device. Unlike the OTA update, which installs over the phone's current software, this method will wipe everything out. So unless you don't care for your files, make sure to make a complete backup before doing the manual install.
Second, you need to become a developer and enable USB debugging. To do this, go to Settings > About on your Nexus 4 and tap on the build number seven times. This will automatically make you a developer. Now, go back to Settings, where you'll find the new Developer options. Tap that and make sure that USB debugging and Enable OEM unlock if you are upgrading from an older version of Android Lollipop are checked.
Third, you will need to install ADB and Fastboot to your PC or Mac. These will allow you to connect your Nexus 4 to your computer via a USB cable and flash the factory image from there. To install ADB and Fastboot for Windows, download the ADB installer for Windows found on the XDA developers' forum. Once downloaded, run the file as administrator and type a Y, which stands for Yes, to install ADB and Fastboot and the related drivers.
On a Mac, the process is easier. Simply open the terminal on your Mac and paste the following code from XDA. This will easily install ADB and Fastboot system-wide without the need for messy installers.
Alternatively, you can download the Android SDK from the Android Development website and follow the instructions for installing it correctly. This will automatically install ADB and Fastboot, which are located under the Platform > Tools folder.
Fifth, the bootloader needs to be unlocked. Manually installing Android 5.1 using a locked bootloader simply will not work. Once your Nexus 4 is connected to your computer, open command prompt on Windows or terminal on Mac in the ADB folder and type adb reboot bootloader. In Fastboot, type fastboot oem unlock. You will need to follow the instructions to unlock the bootloader and erase all data.
And lastly, sideloading a 174 MB file will need a lot of resources, so make sure you have at least 80 percent of battery life to see you through the entire process.
Once that's done, you can now start flashing Android 5.1 on your Nexus 4.
Step 1: Download the ZIP file from the Android Development website. This is the official Google file that will update your Nexus 4 from Android 5.0.1 straight to Android 5.1.
Step 2: Boot your Nexus 4 into bootloader mode either by typing ./adb reboot bootloader into the command prompt or terminal or pressing the volume down and power buttons together while the phone is turned off.
Step 3: Once in bootloader mode, go to recovery mode. Press the volume down button twice and the power button once to select Recovery mode. This will show an Android icon with a red exclamation point on the screen. Hold the power button and press the volume up button. You're now in recovery mode.
Step 4: Flash the factory image. While in recovery mode, press the volume down button once to highlight apply update from ADB and select it by pressing the power button once. In command prompt or terminal, change the directory to the location of your file, then type ./adb sideload [name of OTA file].zip to start pushing the update to your Nexus 4.
Step 5: Wait for your device to finish installing Android 5.1. Once complete, your Nexus 4 will automatically restart and boot in normal mode.
Congratulations! You now have Android 5.1 installed on your Nexus 4.
Google also released the factory images for the Wi-Fi and LTE versions of the Nexus 7 2013 recently, and you can also use the method detailed above to install the updates to your tablet if waiting for the OTA seems like a lifetime to you.
Photo: Kārlis Dambrāns | Flickr