Its couple of months Google has announced its latest mobile OS, the Android 6.0 Marshmallow but it will take quite a few time for this ROM to reach you as your device manufacturer might delay to push the latest flavor of Android to you, same is the case with Samsung, if you own a high end Samsung device then you will get update but when there is not confirm date for as of now.
But we have some good news for you, if you have Samsung Galaxy Note 4 then you can enjoy the Android 6 Marshmallow on your device, the makers of worlds most popular custom ROM, the Cyanogen team has launched CyanogenMod 13 for Galaxy Note 4 which is based on Android 6.0 Marshmallow.
This ROM is still in developing phase and might have some bugs, but as of now most the features are working find and users haven’t reported any major bug.
Disclaimer :- By following below mention steps, Your warranty will be void, and if anything goes wrong with your device, like it stop booting up or anything else then TechnoArea Team will not be responsible for it, its only you and you will responsible for that. So proceed at your own Risk.
Before doing anything we suggest you to make nandroid backup which will backup your ROM and system files, for this reboot into your recovery and select Backup and check all options like System, Data, Boot, Recovery, and EFS.
Download ROM, Blobs and GAPPS from the link above and put them in your device internal memory,
Reboot in Recovery, for this power off your device and press and hold the Volume Down and Power keys at the same time until you see TWRP logo
We need to perform full wipe leaving internal storage, for this tap on Wipe, Advance Wipe and check Dalvik Cache, System, Data, and Cache and then Swipe the slider to perform wipe
Now return to TWRP main menu, and tap on Install,
Now select the ROM file and swipe slider to flash ROM
Now again select Blobs and GAPPS file and flash both of them
Once done just reboot your device.
If you see new boot logo then it means you are done and you will soon see your new OS, it might take some time to boot first time, if you encounter any error or stuck in boot loop then repeat all steps again or restore your old ROM from nandroid backup which you had made earlier.