Hello, I was wondering if there was any way possible to retexture the skins of aircraft in Flans Mod. I am trying to change the texture of the Boing 707 in the civil pack. I am also running the mod on 1.8. I tried changing the skin in photoshop, but whenever I changed the skin it would cause Minecraft to crash when I would load the mod with the changed texture. Does anyone know how you can change the skins of the aircraft correctly?

thank you,