When you are ghost you have to blow up the helicopter in north point 2. use these steps and you are easily going to win.

1. go into the hacking on the select menu
2. if you don't have the cheat thing on the left hand side type cheat after A:/>
3. select the cheat option and put in FFFFFFF1 this will make you invisible to the enemies
4. get to the north point 2 lvl and stand in the middle of the room with the zommed view and follow the heli while shooting
5. when the men come in the middle i think it better if you use a grenade because its quicker but its just as funny using the silent death (go behind the guy and press Z when the green hand appears
6. keep doing this until the heli explodes and your on to the next level


P.S to make sure you have the best guns and grenades put into the cheat thing in hacking: 0034AFFF for all weps. and to make sure you dont die put in: 7F4DF451 for unlimited health