Get on the dirt bike and follow the train. You’re going to want to take the next dirt road–that way you can transfer onto the train tracks, and get behind the train.

Get to the side of the train and bridge the railing.

Get over to the elevated dirt path on the right. Do a jump off the ramp at the end. You will land on top of the train.

Go forward on the train cars.

You will change over to Michael. Drive the boat into the river. Drive to the yellow dot on your map. You will reach the rail bridge.

Get over to the nearest orange car of the train. Have the rear doors facing towards you. Put a sticky bomb there and blow open the doors.

Change over to Trevor and get cover behind the tree in front of you start shooting once you approach the Merryweather boats.

Take out passengers of each enemy boat before you move on to the next boat. Kill the pilots of the helicopters.

Get your sniper rifle out to look up towards the train. You will see a car hanging off the side of the rail bridge.

Activate your rifle’s thermal scope and look left towards the bottom of the bridge to locate more enemy snipers.

Snipe the pilot of the next helicopter that appears and take out the enemies that parachute onto the hillside below it as well.

Get in the dingy with Michael and open fire on the drivers of the Merryweather boats in pursuit until you reach the mouth of the river, then approach the getaway vehicle on land to complete this mission.

Best Cheats to Use for this Mission:

Give Weapons:
PS3 – Right, X, Right, Left, Right, R1, Right, Left, X, Triangle

Xbox – Y, RT, Left, LB, A, Right, Y, Down, X, LB, LB, LB

Invincibility:

PS3 – Right, X, Right, Left, Right, R1, Right, Left, X, Triangle

Xbox – Right, A, Right, Left, Right, RB, Right, Left, A, Y

Explosive Bullets:

PS3 – Right, Square, X, Left, R1, R2, Left, Right, Right, L1, L1, L1

Xbox – Right, X, A, Left, RB, RT, Left, Right, Right, LB, LB, LB

Big Attacks:

PS3 – Right, Left, X, Triangle, R1, Circle, Circle, Circle, L2

Xbox – Right, Left, A, Y, RB, B, B, B, LT