This cheat will let you change how easy/hard the game is.
the file you need to find is under you My Documents folder, not the Freelancer Game folder. "My Documents\My Games\Freelancer" is the path name. Once there, open the file named PrefOptions.ini. *Note*: This cheat has to do with modifying this file. It is suggested that you make a backup of the file first.
Once you're in the file, look for a line that reads "DIFFICULTY_SCALE = 1.00". It's possible that the number is different.
Change this setting to be higher to make the game harder, or lower to make it easier. Make it 0.00 to be invincible.