Note: Make sure to leave at least one Item space available for the ID Card you have to get.
You'll start at Ruinas de Xochiquetzal (the last area from the previous OPS). There are 4 soldiers in this area. One patrolling the western path and the other one patrolling the entrance. Follow the western path first and go west at the fork (where the dead end is) and you'll find a POW here. FRS him out of here, grab *Ration 5 x3 and leave the ruins, but beware of the soldier patrolling outside.
The 2 snipers that were here are gone, but instead there's a scout and a sniper just in front of you when you enter the area on the lower level of the area. You'll see that the scout is looking to the south so move north, approach him from behind and before approaching enough to CQC him, look west and Mk22 the sniper. When you grab the scout, from that position look to the southwest side of the map (where the other entrance of the area is) and you'll see a scout on the left side of the wall and a sniper on the right side of it.
Follow the northern side of the map and approach the sniper from behind. Now take care of the scout and move to the Bottom of the Cliff .
Remember where the sniper was near the entrance? Move to where he was and equip your NVG to see another sniper but this one is on the left side. Go to the west side of the map and look south with the NVG on to find another sniper. What you have to do is to proceed through the middle sector of the area taking care of the one on the left first and then the one on the right side. Now proceed southeast to Catarata de la Muerte .
You may or may not find your man here. If not take care of the scout patrolling the area (use the Sound Indicator) and proceed southwest to Selva de Leche.
Go southwest as you enter and you'll find a scout hiding next to the boulder. Take him out go west a little bit (where the shooting dummy is) and go south a little bit to find another scout hiding behind a tree. Now check directly southeast towards the second shooting dummy to find a sniper. Take care of him and proceed south to the last area.
Once you've retrieved the ID Card return all the way to the AI Lab to trigger a scene. When you regain control do the same thing you did when you fought the PUPA. Start taking out boards in random order to have the scene continue ending the OPS.