Issue making mod

I'm trying to make a van texture mod myself by editing an existing van mod, which DOES work in game.
So I take it, convert from .TEXTURE to .dds, edit what I want to edit, save as .dds and then rename back to .TEXTURE
However, after I make my edits, my mod doesn't seem to work in game. It detects in the mod list but it simply shows the game default van. Does anybody have an idea that could help me out?
Replies
Yeah, the texture tools are great and editing in Photoshop is much easier than most other programs. Cs2 was relatively simple for me personably to figure out, and there are numerous forums and stuff for help. I think you'll enjoy CS much better :D personally I've moved over to a cracked free CS6, just preference, but CS2 still has basically all the tools you'll need to make whatever texture mods you want