m4321

I have a 2011 C300 with leather interior. The headrests in the backseat are tilted too far forward for comfort and I would like to tilt them back. The user manual says I should be able to manually change the tilt angle by pushing on the cushion. Also the slots underneath where the steel rods go into the cushion seem to allow for changing the tilt, but I can't seem to move them. I don't want to push too hard and damage the cushion. Moving the headrests up and down is no problem. Any suggestions? Or maybe the tilt feature is an option and mine are fixed?