and enter the door. go through the door directly in front of you and close it once outside. there should be an opening to the left of the door. walk through it, making sure you hug the wall. once you reach the balcony of the don's office, walk to the door on the right. sneak while opening the door. shoot the don with a silenced weapon, take the keys and whatever else, then walk through the ledge back. as you walk on the ledge, the door to the basement should be under you. carefully drop, enter, do what you need to do, and simply walk out through your entry point 