How to install Stock (original android that came with nexus) Android on Rooted Note5? I want to install the stock Android made by originally by Google that is not Samsung modified without breaking the device. 

Can I return back after doing this?
How can I do,
Thanks!
You won't get exactly the same ROM made by Google because Google didn't make one for Note 5. So let's start with ones that are closer to Vanilla.


Note - You can skip to the last step if you already have a custom ROM installed.

Steps for installing custom ROM

Install Recovery

Follow the steps to install TWRP Recovery for your device. It will enable you to root your device (sometimes this step is included and need not be done separately) and install a custom by flashing (android lingo) the zip file.

Find out your device model

You can find it in one of the following ways


System - Go to Settings > About
Back Cover - Printed on the cover or the battery or underneath the battery
Boot Screen - Restarting the device will show it on screen


Download and Install Custom ROM

Note - Steps for installation is given in respective ROM's forum.


Resurrection Remix is a good ROM, giving you vanilla experience with useful extra features.


Here's the link for ROMs and other cool stuff for Note 5.