Here you can find a detailed description of how to get to CNB H100.5. Pictures of the description can be found below.
Enter through the main entrance of the CAB building. Take the stairs all the way up. Go straight through the hall way until you see a blue stairs on your left. Go up that stairs and to the right straight after. At the end of the hallway go left, through the door. CNB H100.5 is now the last door on your right.