Installing:
[1]Install patch 1.2 if you haven't already.
[2]Unzip the "City_Decedere_zipfolder" and place the "City_Decedere" folder into 'Electronic Arts\Crysis\Mods' folder.
[3]in the folder, click on the Launch City Decedere.bat and select your version
[4]once crysis has loaded, open the console ` and type in... map cityassault2