Take mp-replay_X.Y.Z.zip, where X.Y.Z is the version number, and put it in your mods folder. You can then host or join a game where the other players will simulate the actions of the other players.

I made an issue about a question I had in the Replay Studio Repo and the responder (Johni0702) said: You don't. If you can't figure out how to use something without a wiki, then you probably shouldn't ...