Download the latest version of Rimpy and unzip the folder
https://github.com/rimpy-custom/RimPy/releases
Locate the "RimPy.exe" and open it
Download the mod xml for the server your trying to join and import it through the "import list" button
It might ask to download missing mods, either skip or download them
Press save and then run to start rimworld with your new modlist
