I am putting mointors in both of my headrests and I need to get the wire up the seat back to hook up the monitors. Since I am using the factory headrest the post that holds the headrest is not hollow...so I have to find away to get the wire into the seat. How do the little black plastic rings that hold the headrests on come off (I can get the headrests themselves off)? I figured I would take one of those off....run the wire under it then put it back on with the wire coming out under it. I REALLY dont want to cut a hole in the top of the seat to run the wire through.....HELP!!!