Packie introduces you to his mother and his sister Katie, then he tells you there's some business to attend to at the docks.
Grab a vehicle and follow your GPS to the warehouse at the docks.
A ship is coming in, and Packie wants you to be the welcoming party. You'll receive a cut or whatever's on board. Once you reach the mission objective marker, pull up and watch the short cutscene.
Packie wants you to head onto the roof of the warehouse so that you can get a good view or what's going on.
Head around to the back of the warehouse and climb onto the wood. Jump against the billboard and shimmy along to the end, then drop onto the next section of wood. Jump up and pull yourself onto the vent pipes, then again onto the roof.
After the short cutscene you'll need to drop down and take out all of the people gathered there. The best way is to take cover behind the containers and throw a grenade right into the middle of them. If you have no grenades, it'll be a case of leaning out and shooting at anyone you can hit, then moving back into cover.
Kill everyone outside the warehouse, then clean up any remaining enemies on the docks or inside. Once the area appears to be secure, head inside. There's a health pack on the wall inside the office, so get that then grab the truck.
Once Packie gets in the truck, you'll need to head to the lock up. Not long after you make your way out of the compound, you'll be chased by a bunch of gun wielding maniacs. Niko finds a box of grenades in the truck which you can use to drop out of the window and take out the vehicles behind you. Don't hold onto them too long or you'll blow yourself up.
Make your way to the garage and park the truck, then watch the cutscene with Packie and Ray Boccino.
- It's probably safer to keep the grenades you're given at the end of the mission. It's unlikely you'll kill anyone with them anyway, and they'll either kill you, or give you a wanted level. Plus you get a fair few, and they're $1000 each to buy. Keep them for another mission.