Cant Use My Mods

So basically.. I found a video on youtube with an L96a1 Long Barrel Cross Mod (L96a1 to L115a2) With Black Magnum Textures (That i edited with my insignia. Nothing big.) And TPG sounds. I put the files in my game folder and was ready to go. When i started the game tho i basically got a message saying FUCK YOU by nexon. (Cannot start game due to corrupt client file) or somthing like that. Does anyone know a way to bypass this or make these mods work? Thanks. ^_^

Link to video.
Combat Arms - L96A1 to TPG 115A1 Black Magnum - YouTube