Pursue the Jungle Train

Cafetal Aroma Encantado

While you start in the prison area of the last mission, you'll want to backtrack north east to the Cafetal Aroma Encantado. This facility is heavily guarded and you'll need to sleep every enemy with your MK.22. As you move further into the area, you'll ascend a flight of stairs and into a warehouse. There are more soldiers here, and the narrow movement space make it a good section to use CQC to conserve ammo. When ready, exit through the north ot arrive at a train yard.

El Cadalso

The train yard is being patrolled by around five soldiers. It doesn't matter if you knock them out or outright kill them. As long as the enemies are incapacitated the mission will end.