You will first need to set an Admin Password in the ServerSettings.ini using the Config Editor in the configuration files option of your server's control panel.
To login to admin, open up chat in type /AdminLogin AdminPasswordHere
List of commands
/KickPlayer SteamID or Playername
/BanPlayer SteamID or Playername
/UnbanPlayer SteamID or Playername
/ReturnToLobby
/ReturnToLobbyWhenEmpty
/AdminSay Message
