How to upgrade to Android Lollipop manually

Download the OTA

>The first step to updating to Lollipop using OTA files is to actually download the proper OTA file for your device. The list below are download links straight from Google (hat tip to Android Police for putting these together):

>Note: If there is more than one download option, that means that there is more than one build of Android KitKat available for your device, and you need to download the one that correlates.

>Nexus 5:
from 4.4.4 (KTU84P) to 5.0: hammerhead LRX21O from KTU84Pfrom 4.4.4 (KTU84Q) to 5.0: hammerhead LRX21O from KTU84Q

>Nexus 7 2013 WiFi:
from 4.4.4 to 5.0: razor LRX21P from KTU84P

>Nexus 7 2012 WiFi:
from 4.4.4 to 5.0: nakasi LRX21P from KTU84P

>Nexus 10:
from 4.4.4 to 5.0: mantaray LRX21P from KTU84P

>Nexus 4:
from 4.4.4 (KTU84P) to 5.0: occam LRX21T from KTU84P

>Note: Download links for Nexus 7 2012 3G and Nexus 7 2013 LTE aren’t yet available.

Prepare your Device

>Once you have the OTA zip downloaded to your computer, reboot your device into its boot loader. To do this, power off your device and power it back on while holding the volume button and the power button down simultaneously. You need to get into the recovery from here. Press the volume button until you see “Recovery mode” then press the power button. This should present you with the below screen.

>Lastly, you need to hold the volume up and power button down for three seconds and release volume up to reveal the menu. From that menu, select “apply update from ADB” and plug your device into your computer if you haven’t already.

Install the OTA

>Open up the command line on your computer (terminal for Mac, command prompt for Windows) and change the directory to the location of the OTA file (For example: cd /Users/<yourusername>/Downloads/).

> Now run the command “adb sideload <name of the OTA file>”.

> The name of the OTA file is going to be a long string of letters and numbers and

 will end with “.zip.”

>Once you see “Install from ADB complete” on screen, simply reboot your device. And once you’ve successfully rebooted, you should have the latest release of Android on your Nexus.