The last stage. If you followed this guide, you should now be in the north part of the harbor, near the edge of the map, on the roof of the building with the floodlight. From here you must absolutely eliminate the guards (there is the radio operator among them) in the small building with the antenna, near the stone wall on the west (M4,14). When you finish all objectives you must get there so it is worth to clear the evacuation place earlier.
The vaccines are in the square, near the rocks in the north (M4,12). Approach them to complete this part of the mission. Now, go to the big warehouse near the western rock.
There is not much that you can do inside the warehouse. Try to not be detected. Go through the open doors, turn right and, when the soldier patrolling the warehouse is not looking in your direction, get on the metal stairs. On the top, there is the entrance to the administration room.
Inside, there is the safe (M4,13). The documents, that are inside of it, are your objective. You can open the safe by searching officer's body [codes] that patrols the warehouse with other soldiers (you can track him down by using binoculars) or set an explosive charge. You can blow up the safe without any worries, probably no one will hear you. But if you someone hears you, wait inside for the scout or shoot a barrel in the warehouse to distract the soldiers.
Now leave the building and follow the same path you took to came here and go to the small white radio station building (M4,14) near the western tunnel. If the square is not completely cleared for enemies you can sneak above the tunnel by using a narrow path (M4,7). When you get to the building, use the radio to complete the mission.