If you are more the video guy, user Xammux did a great video tutorial: https://www.youtube.com/watch?v=1MqGO46xdtI
Note: Windows Defender might pop up with "unknown publisher" message. If you don't want to take this risk, you can of course compile it from source.
Mount a tracked controller somewhere on your simulator where it has good tracking. The position does not matter, the algorithm calculates the offset between HMD and reference tracker on its own.
The mounting has to be sturdy. Zip ties, Velcro or Tape will not be enough. See Tracker Mounting for a more in depth-guide
If you use FlyPt Mover as motion cuing software, you can use its calculations as reference tracker. Take a look at this page for more information.