i need help in down load those unique weapons.......but after that i can't get it right......it has got those pink and black stuff came out when i'm in the middle of the game.....i need help pretty bad......hit me if you noe the solution........thanks ^^

First things first, wrong section to ask for skin installation help. This should be under the category entitled 'Skin & Model Installation Help'.
Anyway, the problem you're having is likely because you're not extracting the files into the correct places or, not making the right folders in the right places.
Check you've put the required files into the right folder. Don't forget that you need to make the folder if you don't currently have it.
If you're sure everythings properly installed then it may just be a bad download, and if so, i'd suggest redownloading and reinstalling.