Left Hand 7.1
At the start of the mission, walk down towards the main gate and you'll find three guards nearby. One is patrolling, one is standing in front of the gate and one is standing on the side of the road. The one on the side of the road is the one who has the hand.
Left Hand 7.2
This left hand is just through the main gate. You'll enter a vehicle area with a few guards around. Go to the left side and behind the APCs. Wait for the Heavy Cyborg to walk by and then kill him from behind. Grab his hand.
Left Hand 7.3
Inside the hangar, there are two sides. There's the closer empty side with a few enemies and then the occupied other side with the plane. On the occupied far side, one of the Cyborgs has this hand.
Left Hand 7.4
After exiting the hangar, you'll find three guards near an APC with a Gun Camera watching. The guard on the upper level has this hand. Unfortunately, it's almost impossible to sneak up on him without an EM Grenade.
