Since this is the official CM10.1, not only can you rest assured the software doesn’t have any bugs or issues, but it also brings the latest apps and features found on the CM platform. Additionally, since the CM 10.1 is based on the Android 4.2.1 you will have the same software installed on your Note II with just a few changes made by the CyanogenMode developer.

Before you proceed with the installation of this custom ROM, please make sure the following requirements are fulfilled:

1. Your Samsung Galaxy Note II has to be rooted. In case your phablet hasn’t been rooted yet, you can follow the How-To Root Samsung Galaxy Note II AT&T Version guide.
2. A CWM recovery image has to be installed on your smartphone. For instructions on how to install the CWM Recovery, follow the steps in the How-To Install CWM Recovery guide.
3. Make sure you backup all your data prior to updating your Note II, as you need to wipe all your data in order to flash the CM10.1 JB 4.2.1 ROM using the method presented in this tutorial. You can do so by backing up your Samsung Galaxy Note II using the backup method we talked about before and, to be on the safe side, you should also save the EFS folder.
4. Lastly, keep in mind that updating your phablet with a custom ROM will void its warranty! You will however be able to restore its warranty by downgrading it to stock ROM. This means that you will no longer have root access and the bootloader will be relocked. So proceed at your own expense!
5. Following the steps of this tutorial for a different phone model than I317(AT&T) may brick your device.

Other Requirements

1. A computer with internet connection. You Samsung Galaxy Note II should also have internet connection.
2. An USB cable and microSD card.
3. You should deactivate or even uninstall your antivirus program, firewall or any security program that you use on your computer and phabelt as well, as these programs may try to block the installation of the ROM.
4. Your phone’s battery should fully charged. Under no circumstance start this update if the battery of your device is less than 60% charged.
5. You have to enable USB debugging on your Note II.

Updating Your Galaxy Note II with the CM10.1 Nightlies Android Jelly Bean 4.2. ROM

1. Download the CM10.1 file and save it on your Desktop.
2. Download Google Apps and save the package on your Desktop.
3. Connect your phablet to your computer via the USB cable.
4. Then copy-paste the files you’ve downloaded on your Samsung Galaxy Note II.
5. Now you have to turn off your device in order to enter in the recovery mode.
6. When you see the recovery mode displayed, select Wipe Data Factory Reset -> Wipe Cache Partition.
7. Your device will then be wiped. When this process is finished, select +++go back+++ to return to the main menu.
8. Use the recovery mode menu and select to Install Zip from SD card -> then Choose zip from SD card.
9. Select the CM10.1 file and begin the flashing process.
10. After the CM10.1 has been installed, you simply need to install Google Apps using the same process.
11. It’s important not to make any other changes while on the recovery mode, and wait for the flashing to finish.
12. When the installation is complete, select +++ go back +++.
13. Then select Reboot System Now.
14. Congratulations! You’ve managed to update your Galaxy Note II (AT&T)!

Note: To restore the stock ROM, you need to use the same recovery menu.


See More: Update Samsung Galaxy Note II (AT&T Version) with the Official CM10.1 JellyBean 4.2.1 Custom ROM