Yes, non adjustable .
You just need to push inwards around the top rear of the back rest,
and you will feel the retaing clips that hold the head rests in,
When you find the retaing clips push inwards at the side of the rod where the clip is located. and at the same time pull upwards on head restraint,
once one rod is free, do the same to the other rod, and head rest will come out.
It takes a bit of feeling around to find the clips, but they are there,
and the head rests do come off.