For those who own the Mantaray Wi-Fi Only Nexus 10 and still are waiting for the Android 4.2.2 (JDQ39) OTA update to arrive you can actually do it manually. The procedure is relatively simple and should only take a couple of minutes. What this update does is it has several improvements on the overall user experience.
Prerequisites: You must make sure that your Nexus 7 is currently running on Android 4.2.1 build JOP40G. Your device should also have a custom recovery installed. The latest version of ADB must also be installed on your computer which you can get here.
Disclaimer: TheDroidGuy is not responsible for any damage that may come to your device due to these instructions. Proceed at your own risk.
If you already have the custom recovery on your device then updating it is as simple as downloading the zip file of Android 4.2.2, copying it to your device and flashing it. Otherwise, follow the instructions given below.
Manual Installation Instructions
Turn off your mantaray Nexus 10, and turn back on by holding the Volume Up and Volume Down buttons while it boots.
The fastboot menu should appear and you should see “Start” in the top right. Press Volume Up till it changes to “Recovery.” Press the Power button to select it.
You will see an Android with a red exclamation point icon, press Volume Up and the Power button at the same time.
You will get a new menu and you can navigate to “apply update from adb.”
Connect your mantaray Nexus 10 to your computer via a USB cable
Open the command prompt in Windows (cmd in Windows, regular shell in Linux and Mac) and navigate to the directory that the Zip file is located in.