Oh ya beat me, well here is my guide too
for all the impatient people out there, here i how to get L4D stuff in Gmod:

First, make sure you have the Left 4 Dead demo

1.Download the pvk extractor from here:http://blog.gib.me/2008/11/14/left4d...s-now-with-ui/ (he might update it later, the blog will say what's better)

2.Put the files from the zip in your common/Left 4 dead demo/Left 4 dead folder


3. Run the exe and select the pak01_dir.vpk



4.Extract them to somewhere you want, I just put them in the Left4dead folder (won't affect the game)


5.Find the model you would like in gmod, let's take the survivor models first

Just copy this folder


and this one


into the appropiate gmod folder, for this those would be garrysmod\models\survivors and garrysmod\materials\models\survivors

Note: Delete all the mdl's with anim_ and gestures_ they will probably crash your gmod

6.Now, to make them work in gmod, we need to add some files.

what you do is, go into the models\survivors folder, and copy every .vtx file 3 times, then rename to

*.sw.vtx
*.dx90.vtx
*.dx80.vtx

e.g

survivor_teenangst.sw.vtx
survivor_teenangst.dx90.vtx
survivor_teenangst.dx80.vtx



and done!