Headrest removal / camera mount?

[Dan Sinclair]

Before I thrash my headrests - does anyone know how the Type 89 headrests
come off?   I think they're common to all the Audis of this vintage.  Chrome
posts, open ring headrests.  I'm trying to rig up a video camera mount for a
track event (real important stuff...).  There are two slots to either side
of the post on the backrest portion that look like maybe you'd stick a
screwdriver blade in to release them?  Alternatively, it looks like maybe
you could slide something upward next to the post - but since the headrest
pivots, I doubt that's where they release.  Anybody done this?

Thanks in advance,

Dan
1990 CQ