This tutorial will tell you how to get skins on public servers.

1. Make a copy of your CoD4\main\ before you do this so if you break something up you can redo everything.
2. Go to your CoD4\main and rename the following files: in case you are using other language it will be (localized_LANGUAGE_xx.iwd)

iw_00.iwd -> localized_english_aa.iwd
iw_01.iwd -> localized_english_aab.iwd
iw_02.iwd -> localized_english_aac.iwd
iw_03.iwd -> localized_english_aad.iwd
iw_04.iwd -> localized_english_aae.iwd
iw_05.iwd -> localized_english_aaf.iwd
iw_06.iwd -> localized_english_aag.iwd

3. When you are done with renaming files, copy one of the IWD's to your desktop and call it (localized_english_aw07.iwd) then delete all folders in it using winRAR. Create new folder name it "images", Drag .iwi files (skins) into that folder

Then once you have added the skins to your localized_english_aw07.iwd file Load up Cod4 and enjoy the skins you just added!

Using (hack-looking) skins will cause you to get banned.