Hi buddy , what you need to do is first fold the seat backs down .
Remove the side bolsters by pulling forward then once unlatched , up
remove both side.
Using a flat heat screw driver or door panel removal tool , remove the 4 black plugs on the truck pass through trim panel , pull top towards you and then down.
(optional - remove both c pillars , becarefull not to break any latches and disconnect both opra lights) -makes next step easier.
Lift rear hat shelf up , You'll see 4 posts that go through the uni-body construction that the rear head rest shafts slide into to.
remove the cadimized colored spring clips from each shaft
NOW the head rests will pull up.
reassemble , your done . I wouln't bother re-installing the spring clips again , that way you'll be able to pull out and re install them again at any time without doing any work.
PS: I used to be a moderator for BMWplanet E36 remember