Update.
I found how to do it.

Firstly, you need to disable updating game, it done in properties of game in steam (hope you will find how to do it yourself)

Secondly you need download Steam Depot Downloader [github.com].
It's Purely safe because its GitHub.

Download Zip archive and unarchive it somewhere.

Go to Game Folder and delete or move somewhere all its contents.

Then take .exe file of Depot Downloader and put it in cmd or PowerShell.

Write this command: ./DepotDownloader -app 573090 -depot 573091 -manifest 8455046768499118459 -username <Your username, without parentheses> -password <Your Password, without parentheses> -dir <Your Steam Game Location>



Waiting for download to end.

Go to Steam and just launch Game. be sure it won't update!

TADA, you now have 1.1.18 version of game with all your creations from workshop and addons. But creations will not work due to the difference of game versions they were made on, which will crash game.

Enjoy!

P.S
If your game runs slowly just send in chat "?reload_scripts" it should solve problem.

Soon will made in guide

Aaand Another Update!

I found easier way to do it without downloading Steam Depot Downloader.

Lets get to the Point:

Same as before you need to disable game updating (this tutorial is not about this)

press win+r and write in "steam://open/console"

Then you need to get the appId of game (for stormworks it is 570390)
Then go to SteamDB and go find Depot ID (for stornworks its 573091)
And at last you need needed id of manifest you need (For this mod to work you need this one: 8455046768499118459)

Open console in steam and write this command: "download_depot <id of game> <id of depot> <manifest you need> :"

Press enter and wait for the download to end

And at last you need to go by the default way you go to your steam games like ...Steam\steamapps\ BUT you need content folder now where you find your downloaded manifest.

Have fun!