Finale 2010 mixed up with iTunes

My question is in the subject place above. It was not clear to me that it was a subject line. I'll paste again.

"Stupidly tried to put a Finale arrangement onto iTunes, to see if the sound would go there. I was told by a friend, "Don't use OPEN WITH"! I DID, and now my Finale icons are gone and iTunes icons are in their place. Besides, I tried again to reverse my mess and now I can't even open my arrangements unless i click on "Open WIth". I gotta get this fixed, or else I'll have to confess to my friend what I did and let her fix it. PLEASE, someone tell me what to do.