Can you unplug the cable from the Pimax 8k and 5k+?
Yes. @SweViver made a video about it.
How’d he take off the headrest part?
You don’t need to just, push down on it.
It seemed so effortless in his video but for me it was quite a struggle, and did not even get it off completely but enough to access the cable. I had to apply lot of force which of course I was reluctant to do.