Go to your Modern Warfare 2 install folder and look for iw_07 iw_11 and make of the two files iw a copy (back up)
then you open it the file goes iw07 with winzip or 7zip to images and then add the weapon_fn_fal_new_col.iwi file (for skin )
then you must be one or the ~weapon_fn_fal_new_spc-rgb&we~8dc24d56iwi insert because file in IW11 finished with images
You should at least do a specular map man, give the re-skin some dimension to it. these skins look like you covered the gun in a vinyl sticker all over the place :P it's a creative concept yes, but it needs some work.