- You need a image software like Photoshop, you can try GIMP, is a free software, many people uses it.
- You can find the textures of all the ships inside "maps" folder, if you don´t have it yet.
Sometimes some of the data is stored on compress format *.vp , if so, you need to decompress them first.
- There are several types of textures that the game uses, pay attention to that, some of them...
Diffuse : Is the most important, the base texture, in this is where you can draw your changes, colors, etc...
Normal : Gives the feeling of 3d
Glow : Used to make lights and make them shiny
- You can use PCS2 ( POF model Viewer ) to see the changes without using the game.
Here some nice tutorialshttps://www.hard-light.net/forums/index.php?board=266.0