the vinyl covered masonite kickpanel under the rear seat simply pulls
straight off.  there are 2 springloaded C clips that clip over the  seatbottom
tubing frame.   grab ahold of the kickpanel and pull it  straight off.

then, you can access the bolts that hold the seatbottom.

i dont think the rubber covers from a late model sofabed van will fot over
those early style seatback release studs sticking out of the wall but you
can  try it.

if it were me i would ditch that rear seat and install a sofabed from a
later model vanagon. :)   i actually have a brown corduroy rear  sofabed
cushion from a '85 vanagon that has no a/c pillar cutouts.. have tan  velour as
well.

In a message dated 1/29/2014 4:48:31 P.M. Eastern Standard Time,
jim.felder@GMAIL.COM writes:

I'm  trying to figure out how to get under the rear seat of "Fifty Shades
Of
Brown," my new-to-me 1982 diesel tintop.

The rear seat back has a  catch at each side that does, in a crude way, what
the later center-lever  release does on later models: it lets the seat come
forward in an  irritating almost-useful zombie position that is neither up
nor down,  pressing against the seat bottom and not going flat.

However, the Owner  Manual for the car says

"The rear seat bench is secured with one bolt  on each sidewall underneath
the seat covering. Remove both bolts and take  out the seat. The backrest
portion of the bench should not be  removed."

Huh? What two bolts are they talking about and how do you get  to them or
even find them? You can tell it's too cold here to mess with  this thing
much. And why does it say nothing about the latches on the  backrest?

Does anyone know where I can get the rubber grips that go on  the metal
backrest latches? The bare metal looks like an accident waiting  to happen.

Jim