Axel_of_Sweden and Edilberto's tanks skin mods, with critiques applied in photoshop format with the layers left in to show what is being done. To use this as a mod, load in photoshop/or gimp then just merge (ie. flatten) the layers and save as TGA format.
as suggest in the comments to the original mod's authors. Copy a layer of the originals (from the game) on top of your modded skin, then apply it as a filter with around 50% opacity in softlight, hardlight, color burn or whatever looks best. Fiddle with the contrast and sharpen and sharpen edges a bit. I did it with your skin and it worked wonders on it, with just 5 second of work. Then since i had time added a few more details (like snow flakes in the wheels) and/or added a noise layer and/or tinted the wheels/tracks to match the tank body. another final suggestion ALWAYS apply colors as a layer first and as a color filter (that way u dont loose any of the details) in total probably less then a few minutes to spiffy up the 4 skins.