Instructions
Make a right as soon as you can once you enter the dock building. There is a Colt .45 hiding in this nook. This weapon is key to your survival.
Follow the marker on your in-game map as normal, which leads you to the wide floor below containing several crates. As soon as you enter the floor, the betrayal cut scene plays and several men with chainsaws begin to trickle into the room.
Pump the "X" button to sprint faster as you run. The chainsaws deal enough damage to kill you in one hit -- two if you have on full body armor. However, your Colt .45 deals the same damage to your enemies.
Turn around, press "R" and then "X" once. Only do this when you feel you have a fair distance between you and the nearest enemy. A good way to judge this is if you cannot see the enemy onscreen anymore. This must be done in a very fast motion before running again. Doing this will make Toni turn around and fire one bullet, defeating one enemy. Immediately resume running.
Repeat steps 3 and 4 until all enemies fall. This can take upwards of 10 minutes. Once all the enemies fall, another cut scene begins to play, showing your friend barging in with a machine gun.
Hide behind one of the crates as your friend empties his clip. As soon as you hear the bullets stop, walk away from the crate and shoot him twice to end the mission.