Install Realism Overhaul with all its dependencies for KSP 1.8.1.
Install Real Solar System.
Install RP-0.
Place the modded Real Solar System folder in the GameData folder and replace all.
Go to RP-0 folder, delete the CONTRACTS folder and replace with the modded one.
Open the game and create a new carrer on Mars. Enjoy :)

This is a project i'm doing just for fun, there's probably some things wrong, just so you know.