You will start by standing at the foot of the staircase to you left. Turn around and stand on the other side of the staircase. On the other foot of the staircase. Once you've done that, turn left and walk inside this large are. Continue to walk straight towards the windows standing on the right side of the table on your left. Once you are in front of the steps towards the window. Turn right and you will see a large opening. Walk inside this room and stand in the middle of this empty room and you're done.