The GSM Non-LTE version of the Samsung Galaxy Note 2 is still supported by various custom ROM developers, as there is a brand new unofficial CM13-based ROM available for download.
If you are looking to update your Note 2 N7100 to Marshmallow OS, then you should follow all the instructions that I've listed in this post. This new custom ROM is based on AOSP Android 6.0.1 and on some CM 13 builds ported from other Galaxy Note versions.
Ivan_Meler from XDA is the developer of this unofficial CM 13 Android 6.0.1 build and you will find the following things working 100% after the installation is done: OpenGl, MALI blobs, Rotation, Wi-Fi, Camera, NFC, Bluetooth, all Sensors, HWComposer and MALI R3P2 drivers, home button wake, RIL, vibration, Pin Lock, Mouse Pointer, Signal Icon, GPS, external sdcard mounting, soft keyboard on first boot, and tons of other small things.
Note: some video applications might show some force close errors while media playback is in progress. Before starting the installation process of this new custom ROM you should check the guidelines below.
This is a tutorial that you will need to use only with the N7100 Non-LTE Galaxy Note 2 models.
Go to Settings> About Phone and look for the N7100 version under Model Number.
Don't try to update any other different Note 2 models with the files that you will find in this post.
Your smartphone has to be rooted, obviously. Also, a custom Recovery has to be installed on it.
The custom Recovery should be based on the latest version of CWM or TWRP Recovery versions.
Make sure that the installed recovery is updated to its newest build, so that it will support the latest Android 6.0.1 custom ROM installations.
In the tutorial you will find two extra preparation steps like NANDROID Backup and the Factory Reset ones. Do not skip these steps.
The NANDROID Backup creates a full restore point for your smartphone, one that can be used to fix your device in case the new CM 13 Unofficial build doesn't boot.
The Factory Reset wipes clean the system partition, but it won't delete any data from internal nor external storage.
Factory Resetting the Note 2 will allow the new ROM to boot in normal mode after all files are installed.
If you need to save any data from installed applications, then you should try to use Helium app
Contacts info should be synced with your default Google account.
This tutorial is destined to be used by advanced users only. We cannot be blamed in case you brick the phone nor in case you end up deleting any important files.
Read the entire post and do not skip any steps.
Check battery charge level, make sure that it is over 50%, so that the Note 2 device won't power off during the installation process.
These were all the preparation steps you had to go over before starting the custom ROM installation.
How to flash Unofficial CM 13 Android 6.0.1 ROM for Samsung Galaxy Note 2 N7100:
Download the CM 13 Unofficial ROM zip from here.
Download the Gapps for CM 13 /Android 6.0 ROMs from here.
After the downloads are done you need to move both zip files to your phone's internal storage.
Do not unzip the files, but disconnect the device from PC after the files are copied.
Power off your phone.
First thing that you need to do is to create a full NANDROID Backup for the ROM that's already installed on your device.
For CWM-based Recovery: select 'backup and restore'.
For TWRP-based versions: select 'backup'.
Set a name for the backup file and confirm process.
Next, factory reset the device:
CWM: select 'wipe data/ factory reset'.
TWRP: select 'wipe' option.
Confirm process and continue to the next step when done.
Start the CM 13 Unofficial Android 6.0.1 installation:
For CWM: select 'install zip from sdcard', then 'choose zip from sdcard'.
For TWRP select 'install'.
Find the Unofficial CM 13 zip file and confirm the flashing process. Don't press any buttons until the installation is done.
When the custom ROM is done installing on your device you can flash the Gapps zip in the same way.
After all the new Unofficial CM 13 and Gapps files are installed on your phone you can reboot the Note 2 N7100 device in normal mode.
NOTE: the first boot process of this new custom ROM is going to take at least 10 minutes before it loads all the new files.
Use your default Google account info in order to regain complete control over your smartphone once again.
I hope that you've managed to complete the CM 13 unofficial Android 6.0.1 custom ROM installation. But, in case you've encountered any problems completing the guide, then you will make sure to read the extra info below.
If the first boot process of this new custom ROM takes too long to complete and the 'optimizing apps' menu doesn't show up, or in case your Note 2 device enters in a boot loop, then you will be forced to repeat the whole tutorial more than once.
In case you repeat installation, then you will have to make sure not to skip any steps and that your Note 2 device meets all requirements listed above the tutorial part of this post. Also, use the comments field below in case you need any extra help.