Simply complete the level, "The Chase".
This is level #21 and is across the bridge from the starting island. If you follow the train tracks around from the right-hand side, down and around, you will eventually come across a tunnel, this is where the level starts!
The level itself isn't too hard, just be careful when changing the train car and getting taking/throwing packages back to the truck!
Bonus Objectives: (not needed for this achievement)