1. Place "Favela" file inside:
C:\Program Files\Steam\steamapps\common\left 4 dead 2\left4dead2\addons
2. Load up Left 4 Dead 2 and click "Extras" on the main menu then click on "Addons"
3. Mark and add the map to your addon's list
4. Select Survival gamemode from the main menu and either start your own local server or attempt to find and join an online server
Enjoy playing and thank you for downloading!