Get inside the helicopter and fly towards the blip. As you go, Little Jacob says that there's a rocket launcher on board and he will personally take down Borodin from the helicopter. The target is in another chopper, flying around Liberty City, and you'll need to follow him and wait for an opportunity to take it down. United Liberty Paper. doesn't want any civilian casualties, so you'll have to wait until the target is flying over the water before firing a shot at it.
Chase the target in the helicopter until you get to sea - an area with no bystanders or witnesses. Get to the same altitude and go to the right of Borodin's helicopter. This will give Jacob the chance to shoot the helicopter. After a few shots, Little Jacob will hit the helicopter.
You will see a cinematic execution where the helicopter is on fire and falls towards sea. It explodes before this happens, therefore killing Eduard.
After this you have to land the helicopter on the helitours helipad to complete the mission.