Download the minecraft_server.jar 1.4.6 (Get MVC, scroll to Minecraft 1.4.6 and click download server)
Open it with 7zip or winRAR.
Get forge universal 1.4.6
Get player api 1.4.6
Install forge universal.
Install playerAPI.
Go to the folder your minecraft_server.jar is.
Make a new folder called mods.
Put terrafirmacraftBuild75.zip in there
Open the minecraft_server.jar
Make sure it runs successfully.
Done.