After fighting Jack Baker in the garage of the main house you'll obtain an Ox statuette which lets you into the main hall. There is a shadow plinth on the opposite side of the room. Before going to it, grab the clock pendulum out of the grandfather clock in the main hall. Now use it on the shadow plinth and once you exit out your achievement / trophy should pop.
Here is a video guide with English commentary!
Here is a playlist of guides for this game!
https://www.youtube.com/playlist?list=PL-HeW6XkKdUKUtj7CV_kW...