Friend owes me money and wont pay

If you are talking about the web based XML files those are editable. PDFs aren't to editable, but there are ways around those too.

The XML I am referring to is when I save conversations they, or one of my friends ahd witht hem where he admits what he owes to them or that he'll pay it back its archived in an xml format on my computer lsiting only the date and time of each comment it wont let me cut or paste or anything. I'm thinking if I print those off and bring a copy in on floppy it'll show they havent been modified right? would that be admissable?

Go to your court house & file papers, it usually cost $45, Make copies or everthing you have to leave with court, when date comes up, make copies again of everything, so you turn in orginals for evid, & you still keep a copy. Did you withdraw from saving to pay for flight, have your bank statement.
Next time, get a signed statement when lending money, whether to friends or family.