NV4500 transmission backup switch...

For my continuing nightmare working on my '97 K3500, how on earth do you
get to the backup switch on the NV4500 transmission?

The manual is very vague about it and the poor diagram seems to indicate
that it is mounted on the side near the top of the trans just in front
of the shift tower. This location is so inaccessible from underneath
that I can't even locate the wires going to it and there looks to be
about 1.5" clearance to the floor. There are two fuel lines and like
four wire harnesses going by so you cant even reach up and feel around.
Is it accessible from the top by removing the shift boot perhaps?

Thanks,

Pete C.