• Download the latest Multiplayer.zip file from here: https://github.com/Parexy/Multiplayer/releases or from the steam workshop: https://steamcommunity.com/sharedfiles/filedetails/?id=1752864297

• Unpack the downloaded file into the Mods folder in RimWorld's installation folder

• The mod's folder should be Mods/Multiplayer/ (make sure it's not: Mods/Multiplayer/Multiplayer/)

• In the ingame mod list, enable and order the mod right below Core (Core->Multiplayer->other mods)

  

• Connect and play using the Multiplayer button

  

If the button still doesn't appear make absolutely sure you've downloaded the mod from here: https://github.com/Parexy/Multiplayer/releases

You can safely delete the Multiplayer folder if you are updating the mod.

(The mod isn't available on the Steam Workshop yet)