
You need both squawkbox and relay for 2004. If you go to Ivao site, you will find easy to understand instructions in the software or tutorials sections. Also d/load a small programme called Host SB.
To try to give you instructions in any depth here would take to much time. It all seems a bit daunting at first, but once installed and used a couple of times, soon comes easy.
I would suggest if you are still unsure, try d/loading Roger Wilco voice (free) or Teamspeak (free) get a cheap headset with attached mike, and someone would, I am sure, talk you through, word for word.
Tony