How to Downgrade to 1.6.1170 (REQUIRED)

How to Downgrade Skyrim

How to Downgrade Skyrim with Reliquary (Recommended)

Download and open Reliquary HERE
Sign in with your Steam credentials. This only connects to the Steam servers directly.
Select version 1.6.1170 and hit "Switch to 1.6.1170"

How to Downgrade Skyrim Manually

Download the Skyrim Downgrade Tool HERE
Unzip the file to any folder
Run the "Run Downgrader.bat"
Copy and paste the commands on screen into the Steam Console one at a time. (Wait for it to download completely, it will notify you)
Manual commands:
download_depot 489830 489831 8442952117333549665 download_depot 489830 489832 8042843504692938467 download_depot 489830 489833 1914580699073641964
Once they are all downloaded in the Steam Console, press ENTER in the Downgrader terminal.
Make sure that you restrict your Skyrim updates on Steam:
(Go to game Properties in Steam > Updates > Automatic Updates > Wait until I launch the game)