8-Ball, knowing about the meeting after a phone call from Salvatore Leone, tells Claude that he needs $100,000 for the explosives and tells Claude to return when he has the money. After obtaining the necessary money, Claude returns to 8-Ball's and the two head to Portland Harbor, with 8-Ball giving Claude a sniper rifle, since his hands are still in a condition bad enough to handle a weapon. After arriving at Portland Harbor, Claude gets a good vantage point (likely the staircase on the warehouse) and begins to kill the Colombian Cartel gang members guarding the Les Cargo container ship, with 8-Ball planting the explosives. He detonates the explosives, getting off the ship's bridge just before it sinks.
Take the adrenaline pill just around the corner of the warehouse complex. That will make aiming a lot smoother.
The reward for completing this mission is $150,000 and the mission Last Requests is unlocked.