Install:

1 -  Open steam console command:
steam://open/console

2 - Download "Windows Content" depot and then "Common Content" depot:

Steam console commands:
download_depot 212070 212071 2585018241621864347
download_depot 212070 212072 7077598683609071450

3 - Copy "data" folder from
\Steam\steamapps\content\app_212070\depot_212072

to 

\Steam\steamapps\content\app_212070\depot_212071

Now, depot_212071 is the game folder, you can copy it everywhere you want.

4 - Unpack SC_Instance_Launcher.zip to x64 game folder:
[Game folder]>\win64

5 - Make a shortcut of game.exe
Create a "-multiCopies" parameter for the shortcut (in Properties):
"C:\Program Files (x86)\Steam\steamapps\content\app_212070\depot_212071\win64\game.exe" -multiCopies

Usage:

1) Open Server instance

2) Press End (You will see console)

3) Open "Client"

4) Press End (You will see console)

5) Open F2 menu on both 

6) Choose mission, select bots and click "Start" in Client 

7) Go to Server instance and click "Connect" 

8) Continue playing on Client instance

Note: Any game can be a "server" and "client".

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Disclaimer: Provided for demonstrative and research purposes only. The SC Outpost and the maintainer(s) are not responsible for misuse of this tool.