Showing Sheet Music for Specific Instrument

Didn't know where to put this, hope this is the right place. What I'm trying to do is open an MP3 I downloaded, and see the guitar notes in MuseScore. RIght now, I can only see piano notes, which is not what I want to see. I how can I set it up to see to show guitar notes or only certain voices?
Thanks, rokingpug.