help returning to gnome fallback

[Kenny Hitt <hittsjunk@gmail.com>]

Hi.  After the last upgrade my default session has changed to gnome shell.
This makes my gnome session useless.  After i hear orca say "welcome to orca", I get no
more feedback from the system.  Would someone sighted please provide me instructions on how to return to an
accessible gnome?  I haven't been able to make gdm3 accessible, so your instructions will need to be done with no
feedback from my system.
This would be a good thing to document in the release notes because it's likely to happen to other users.
If it is already documented somewhere, please point me to the documentation.
I could just purge gnome-shell like pulseaudio.  If that's the best answer, then it
needs to be documented as the solution for gnome accessibility in Wheezy.

          Kenny