Leave the room and loot the weapon lockers to get a weapon and a tac-vest. There’s an enemy trying to break open the door so kick it open and kill him by surprise to get a trophy (Never saw it coming) You don’t have silenced weapons with you right now but it will still be beneficial to remain crouched when moving around to prevent the enemies from tracking your position. Take out the guards in the balcony then move downstairs. Open the door there to trigger a cutscene.
After the scene, take cover immediately and take out any enemies that will be standing in front of you. Once cleared, circle around the courtyard and stalk the other enemies. Use the many covers here to vault into position and hide from enemy fire. Make sure to walk over the corpses to collect their ammo. Use your intel view to keep track of their movements. It will be better to get rid of all of them to lessen the risk of getting flanked or shot from behind.
Fight your way towards the marker. After eliminating the enemies in the courtyard, head to the shed and kick the door open. Kill the torturer by blasting him or shooting the explosive canister beside him. There’s a vargas painting in this shed as well so collect it first before untying DeGarmo.