It's been a few years since I did this, and of course I'm not looking at
mine right now, but...
  As I recall, what you want to do is modify the case a little.  I believe
you take a hacksaw blade or similar impliment of destruction and make a
vertical cut at the bottom at each side so as to remove the strip that goes
along the bottom front of the core.  Thenceforth the case can be removed
without much hassle.

Larry A.

On Sun, Oct 26, 2008 at 11:44 AM, Jim Johnston <inmytree1@gmail.com> wrote:

> Vehicle: 1991 Vanagon GL
> Location: Wilmington, NC
>
> Hello all,
>
> My rear heater core has sprung a leak.  In looking at getting to the core
> and valve, It seems that I have to remove the rear bench because the bar is
> blocking the removal of the cover.  I just wanted be sure that is the case
> before tearing things apart.
>
> Jim
> Wilmington, NC
>