Installing Killmarks
Although it can seem slightly confusing or daunting at first, installing mods is actually pretty easy.
First off you want to find out where you installed CrossFire to. Note that this is not the folder found in your My Documents folder but the folder in your Program Files folder.
Next download the killmarks you wish to use.
Extract the files from either the .ZIP or .RAR you downloaded. You need WinRAR to extract .RAR files, it can be found here.
Most killmarks only have a Mark folder while some have both a Mark and a Scripts folder.