Insanity: is doing the exact... same f**king thing... over and over again expecting... s**t to change.
Go to My Documents/My Games/Far Cry 2/Usermaps
unzip the zip file you downloaded and move it there, open your multiplayer mode in far cry 2 and go Online/Offline and host, select my map from the map list and there you go!
ENJOY THE INSANITY!!!