So where do I find such thing? When I'm in their manor, quest marker points at exit door. When I'm outsiede, the marker points inside... 
go to the balcony outside of his chamber and you should be able to jump forward onto a platform attached to the roof. follow that to the door on the other side of the manor to get inside :p
Thank you kind sir. I'll try that at once. 
Profile - DevilSauron
Profile - sleedroc
Profile - DevilSauron