https://www.youtube.com/watch?v=VYMAHjhJUPM
This video shows the arm and the link positioning. The arm, which is connected to the relay and the link is connected to the arm. Going over center means the arm is when the arm is face toward the passenger side rather than the driver's side as in the video.
https://www.youtube.com/watch?v=M_VxT6h5bQE
This video is not an E53 but the same principles and testing procedure apply.