To replace files quickly and properly, follow these steps:

1. Go to Steam > Scrap Mechanic > Properties > Local files > View local files

2. Go to the /Data/ folder Gui and drop the Fonts2 and Layouts folders there

3. Return to the Scrap Mechanic folder and follow the path /Survival/Gui/language and drop the Russian folder here

4. That's it, you can enter the game , set the Russian language in the settings and play!

Video instructions - imgur

Error in translation? write to telegram - @shandeika0

Translation is about 75%. Sorry, I only managed this in one night.