Extract to C:\Program Files (x86)\Steam\steamapps\common\Counter-Strike Global Offensive\csgo\maps if running 64 bit windows. 

Extract to C:\Program Files\Steam\steamapps\common\Counter-Strike Global Offensive\csgo\maps if running 32 but windows.

Nav file is not need to play the map CS:Go will create it for you if you try to play the map with bots. I just included the file if you wanted to bypass the loading and get straight to pwnin.