I've already read the tutorial made by jimbomcb but, I may be dumb but I don't understant that part:
It's simple, extract the 'l4d2_fix' folder into your SourceFilmmaker/game directory. Mount the content like you would any other game by adding the mounting line above your left4dead2 mount in your usermod/gameinfo.txt. This ensures that the fixed content has priority over the broken content.
If you haven't done so already, run the batch file that fixes invisible models. http://forums.steampowered.com/forums/showthread.php?t=2824377
- see step #3, run it inside your left4dead2 folder.
Now, when you load SFM, left4dead2 content should be functional.
Just for reference, here's my gameinfo searchpaths.
In the usermod, I went to the gameinfo.txt, I saw the searchpaths, but didn't have the "l4d2" one, so I pasted the "l4d2 fixes" one, and here is what I have:
Couldn't do better, I dunno why. Also, I can't see any model or map when I launch SFM (even with a "Rescan". But SFM doesn't crash, so that's okay.
I really need a hand right now, thanks in advance :s