Saint Mark's Bistro/Walkthrough

When you start off, the "back-up" you chose, Ken Rosenberg, Kent Paul and Maccer will leave Las Venturas for Los Santos and you'll have to pull this alone. Get to the airport and get in Salvatore's Jet, then fly yourself to Liberty City. When you arrive, a Taxi will take you to Marco's Bistro in Saint Mark's.

When you enter, the guards won't let you through, so a shootout will begin. First you'll have to shoot the guards in the entrance, next are the ones in the main eatery and next the guards in the service hallway. Now enter the kitchen and kill the guards there, finally, move on to the parking lot and kill the bodyguards there along with Giorgio Forelli (Though the fact that the killed Forelli Family member was Giorgio Forelli is not confirmed). After killing the target, you'll automatically be back on Salvatore's Jet, headed to Las Venturas.

Fly the same way you came and then land the plane on Runway 3, then get off of it to complete the mission.