1. Go to your Crysis game folder -> Electronic Arts -> Crytek -> Crysis -> Game -> Levels.
  2. Eventually backup existing levels with the same name.
  3. Copy the level folder from the downloaded file into the current game folder (Game/Levels).
  4. Start Crysis
  5. Open console and type in "con_restricted 0" (without "") to allow access to console commands
  6. Load your custom map by typing in "map mapname" (Without "") and press Enter.
Naja,also wie oben eben schon gepostet
oder am besten ist wenn du für SP maps einfach einen Launcher verwendest

http://www.crymod.com/filebase.php?fileid=290&lim=0
http://www.crymod.com/filebase.php?fileid=652&lim=0
http://www.crymod.com/filebase.php?fileid=304&lim=0