How to make an airline in Flight Simulator?

What program can I use to repaint an aircraft for my airline? Me and my friend are looking to make one for FSX, but we can't find a program to repaint an aircraft, and we don't care if its payware either, so if you know a program, please tell us it and where to buy or download it.

Sorry if this is wrong section, but alot of people answer me here.

melo