So you can't wait for the official release of the L4D SDK?
Don't worry, you can set it up old-school style.
Here's how:
First Step- Open up steam and go to Tools tab.
- From there select Source SDK
- From the drop down list select the engine version to be "The Orange Box"
This sets the editor to the newest source engine version.
If you have The Orange Box selected already you don't have to select it again, naturally.
- From the Source SDK panel press the "Create a Mod" button.
- Select Create Half-Life 2 Multiplayer Mod and press Next.
- Now a new screen pops up and asks what is the mod called and where it should be saved. Type "C:\Left4Fake" to the first field and to the second "Left4Fake"
Why Left4Fake? So it doesn't mess anything up when Valve decides to release the official SDK for Left4Dead.
It'll load now for a while. Let it do it's job.
Done? Awesome let's get ready for second step:
Second Step
Link to the .zip will come up when you press the link called
A newer build of my VPK tool that now includes a UI.
- Unzip the files somewhere in your hard drive.
- Now double click Gibbed.Valve.ExtractPackage.exe.
- Press Extract and find the file called pak01_dir.vpk found in Your Steam Install Directory\SteamApps\Common\Left 4 Dead\left4dead\
- Extract the file to SteamApps\Sourcemods\Left4Fake\
This will extract all the textures, sounds and models and stuff like that so you can work with them. It'll take a while.
"As your attoyrney I advice you to use this time to make a hot cup of coffee."
All done? Awesome! Get ready for the most annoying step.
Third Step
This is a tad bit more tedious as the script that would do all the work for you has disappeared to bit heaven. You have to do this by hand now...
- Copy the following to a text file:
Code:
copy *.vtx *.dx80.vtx
copy *.vtx *.dx90.vtx
copy *.vtx *.sw.vtx
del *.dx80.dx90.sw.vtx
del *.dx80.dx90.vtx
del *.dx80.sw.vtx
del *.dx90.sw.vtx
- Now rename that txt to: vtxfixer.bat
- Go to your Left4Fake model folder at SteamApps\SourceMods\Left4Fake\models\
Sidenote: If you cannot find that folder, you have done something wrong. 
- and copypaste that script file you just made there.
- Run it.
- Now copy&paste that script to EVERY folder and SUB folder at your models directory and run it.
The script fixes the model files so that you can use them.
When you are done crack open a cold beer. You are almost done here.
Fourth Step
I extracted mine to SteamApps\MyUserName\sourceSDK_content\ just to keep things tidy.
- Now open up Source SDK and make sure you have The Orange Box engine version and Left4Fake selected from the drop down list.
- Go ahead and start up Hammer.
- Go to Tools -> Options
New screen pops up.
- From the Game Data files, go ahead and remove the HalfLife multiplayer one.
- Press Add and add the file you downloaded earlier and extracted... where ever you did extract it.
- Update the following info to following tabs:
Code:
Game Executable Directory:
$SteamDir\steamapps\SourceMods\Left4Fake
Game Directory:
$SteamDir\steamapps\SourceMods\Left4Fake
Hammer VMF Directory:
$SteamUserDir\sourcesdk_content\l4f
For the Hammer VMF Directory you have to create new folder to that location. It should be made in:
SteamApps\YourUserName\sourcesdk_content
YOU ARE ALL SET!
Fifth Step
- Now make them maps and make me proud.
When you are ready to test your map compile it (without running it) and put the compiled file to your L4D maps folder found in SteamApps\Common\Left4Dead\left4dead\maps\
Start up Left 4 Dead and type the following to console "map yourmapname"
It'll load it up.
To create navigation maps for your map (so that the dumb bots and zombies can run around) type "nav_generate" in console after your map is loaded.
Now add Kebab's reputation and worship him as your god!