Copy the .int files from the package into your System directory.
Copy the .utx files from the package into your Textures directory

Now copy this into your Unreal.ini below the other ServerPackages in the [Engine.GameEngine] Section
You can choose your new Skin in the Player-Setup.

ServerPackages=Female1skinsPiP
ServerPackages=Female2skinsPiP
ServerPackages=Male1skinsPiP
ServerPackages=Male2skinsPiP
ServerPackages=Male3skinsPiP