NOTE: If you’ve already installed a preview of Android using this tutorial, skip to step 2.
Step 1 –
Download the minimal 2MB installer from here(XDA thread) this XDA thread which includes the Android ADB and fastboot tools.
You need these to install the Android 5.0 Lollipop image, and this is the quickest and easiest way to install the tools without downloading the entire Android SDK, which is huge and contains stuff you don’t need to get Android 5.0 Lollipop.
Follow the instructions (don’t change the installation path when asked where to install it) and you should end up with a command prompt window:
Step 2 –
Download the appropriate file for your device from here (Google’s factory images page).
You will also need a utility such as 7-zip or winrar which can extract the files from the .tgz file.
! NOTE: We had to change the file extension of the downloaded file from .tar to .tgz before the .tar file within the .tgz could be extracted.
Now that you’ve extracted the .tar file from the .tgz file, extract the contents of the .tar file (shown below) to a temporary location, such as the desktop. They should be extracted in a single folder called ‘hammerhead-lrx21o’.
Note you do NOT need to unzip the zip file which is highlighted. Leave this as it is.
Now, copy the contents of the hammerhead-lrx21lo folder to your Minimal ADB and Fastboot folder, which should be c:\Program Files (x86)\Minimal ADB and Fastboot.. You will need to overwrite some files if you haven’t cleared out an older Android image from the folder.
Step 3 –
On your phone or tablet, head to Settings, and scroll down to About phone at the bottom. Scroll down to Build number and tap it 7 times. This unhides the developer options, which aren’t displayed in Android 4.2 and later. In the Developer options menu, enable USB debugging.
You’ll need to do this even if you are running the preview version of Android L. And if you are, now skip to step 6.
Step 4 –
Download the Google USB driver from here and extract the zip file somewhere.
Step 5 –
With your Nexus connected via USB and powered on, go to the Control Panel and click Devices and Printers. You should see your device in the list. On our Windows 8 machine, it was listed as ‘MTP’ under Multimedia devices. Right-click on it, and choose properties. Click on the Hardware tab, then select the Nexus 5 in the list, and click Properties. Now update the driver, pointing Windows to the folder where you extracted the Google USB driver. Once done, it should report the device as Android Composite ADB interface. Plus, you should get a prompt on your device’s screen asking “Allow USB debugging?”. Tick Always allow from this computer and tap OK.
Step 6 –
Now, Power off your device, and leave it connected to your computer’s USB port. Now start it using the appropriate key combination to put it in “fastboot” mode.
For the Nexus 5, that’s by holding down the volume up, volume down and power buttons simultaneously. You should see a screen like the one below. Press power and volume down on the Nexus 7.
Alternatively, you can leave your device on and type adb reboot-bootloader to restart in fastboot mode.
Step 7 –
If the LOCK STATE says locked (which it should) then type ‘fastboot OEM unlock’ at the command prompt, without the quotes, and press Enter. (If it’s still unlocked, skip to step 8). You’ll see a screen like the one below. To change from no to yes, use the volume rocker, and to select the option, press the power button.
This WILL erase your device, so make sure you’ve backed everything up first.
Step 8 –
With the boot loader unlocked, you can now install the Android Lollipop firmware. Simply type flash-all and the process will begin. You will see alternating downloading… writing…. erasing… on your device’s screen.
Step 9 –
When the process finished, you should lock the boot loader again for security. Start the device in fastboot mode (as in Step 6), and then type fastboot OEM lock
Locking the boot loader won’t wipe any data, but if you unlock it again, it will erase the device of all user data and settings.
Now, Android 5.0 Lollipop is installed into your device, Enjoy and get back to us for more update on latest technology and How To’s….