Allways backup your main folder first, before making any changes.
Open your "C:\Program Files\Steam\SteamApps\common\call of duty modern warfare 2\main".
Use Pakscape to open your iwd files.
Copy and paste your camo, skin, or sound in the iwd file with the same name as the folder your moded file is in.
So if itís in folder iw_20 paste it in iw_20.iwd\sound\music.
And if itís in Folder iw_7 paste it in iw_7\images.
Make sure to save before you exit pakscape.
You can also use Winzip or Winrar as well but pakscape works best.
You can find Pakscape HERE
Along with a Tutorial on how to modify and replace sound files.
Here are some Camos in this pack:
Contains 23 Camos
Special Thanks to House Hax, Archangel and Abstract for giving me the tools to be able to do this.
How to make custom sound
How to reduce Lagg and increase internet speed
Small texture hack pack