Hey
You should get texView (by BIS) and Paint Shop Pro (by Jasc) first. Then you open all the texture files of the vehicle (beginning with "UAZ_" for example) with texView, then search the one where the insignia is.
Now, take a screenshot of the Desktop (REMEMBER leaving the texView window open) with Paint Shop Pro (if you don't know how to, look in the help files or ask me again) so you have the paa/pac picture in PSP. Now select the only area where the pic is in (be careful: there is a black border around it) and save it as a jpg file.
BUT BE CAREFUL: Paint Shop Pro automatically saves it in size 255X255 for example, but texView and OFP can only display them in sizes 16, 32, 64, 128, 256 and so on, so resize the image.
Now you must have the Texture Swap Utility to open the vehicle's model. So do that and look for the original name of tze insignia texture, and change it to your jpg file name (remember adding a folder name; the Folder name should be named like the final PBO, remember adding a \ at the end). Then save the P3D, PBO it and get ingame...
If that was too much, you can contact me with ICQ/AIM ... ;-)