Hello Madhatter.
Here goes...(takes a deep breath..)
First of all you need to go to your aircraft folder, right click on it and click Copy.
Then click Paste. The computer will now make a copy of the folder entitled "Copy Of Texture"
Rename the folder Texture.myairline (or whatever you want to call it)
Now, you'll need DXTbmp which you can download from
www.mnwright.btinternet.co.ukOpen DXTbmp and click File- Load Extended Image
Browse for your new folder. (Click on it and click the_T folder- e.g b737_400_T or whatever the aircraft is called)
Then go to the right hand part of DXTbmp ( the alpha channel) and click on the button below it (here you can decide what your Default Paint Program will be. I use MS Paint but Adobe Photoshop is thought by many to be the best)
Now click Image- Send to Editor
(This opens your paint program)
When you have finished repainting your aircraft click Save
Go back to DXTbmp and click Image- Reload After Edit
Then click File-Save Extended Image Then go to your Texture.myairline folder.
(You must make sure that you save it in the _T folder or it wont work) e.g b737_400_T
Now, your nearly done, but you need to modify the cfg files.
Go to the aircraft folder (e.g.b737_400) and click on aircraft.cfg. Make a copy of the last cfg file and paste it in below.
Change the flight sim number to the next one up (if the last one was 3 change it to 4)
Change the ATC, ID and UI to myairline (or whatever you want to call it)
Then go into Flight Sim and your newly painted plane should be ready to fly! (If it isnt, try altering the cfg and make sure you havent made any mistakes in there)
Hope this helps
If you need any more help, ask Hagar, he helped me a lot.