John H or ?

I have recently purchased a 1992 300TE with a passenger side headrest that will not move via the switch. I can move/remove it manually. I would really like to see the inside if it is easy. What are the details?

Also, the previous owner seems to have been a heavy weight. The drivers seat cushion (MB-Tex) feels dead compared to the passenger side and my 1986 190E. Any thoughts on replacing innards?

Thanks, JM