Go at it from within the interior cabin, underneath the carpetting. There is an access panel that you can go through, and reach the nut from that side.

Search for this theory/approach, as there are pictures posted documenting this exact process.

'99 CSVT - Silver #222/276 In a constant state of blow-off euphoria.
Originally posted by Kremitthefrog:
I like to wear dresses and use binoculars to watch grandmas across the street.