Turn left and you can see an opened door in front of you, move towards that opened door. Now, slightly turn left and walk in the passage and enter into the room which is in front of you. Right now you're facing towards a small window. Now, slightly turn right and you can see a staircase. Walk all the way down through the stairs. After you reach the end point of the stairs, slightly turn left and move towards the wall which is in front of you and that is the end point.