Install:
1.Download Gibbed's VPK Extractor if you haven't already.
Open it, then extract \steamapps\common\left 4 dead\left4dead\pak01_dir.vpk to
\steamapps\common\left 4 dead\left4dead\.

2.Unrar the rar file to \steamapps\common\left 4 dead\left4dead\

3.Open up whitelist.cfg in \steamapps\common\left 4 dead\left4dead\ with notepad and add:
"add" "materials/models/..."

4.Open up pak01_dir.vpk in \steamapps\common\left 4 dead\left4dead\ with notepad++ and replace:
$baseTexture "models\w_models\eq_medkit/w_eq_medkit" wiht $baseTexture "models\w_models\eq_medkit/w_eq_medkit_1-UP" and

$baseTexture "models\w_models\eq_medkit/w_eq_medkit" with $baseTexture "models\w_models\eq_medkit/w_eq_medkit_1-UP"