h2w,
was waiting for some one that has this model to reply,but so far no one has.
if the body isn't off the chassis look for the screws that hold it on and remove them.
when the chassis drops out look for a screw over the truck that hold it on,remove that
and if its the older drive the truck will drop out.not sure about the newer DCC On board drives ??
the old truck has a thin stamped metal piece that wipes the drivers and rubs the chassis half.
once the truck is out there is a molded clip to hold the sideframe on,lift that slightly and the sideframes
and bottom cover should come off.
be carefull when reassembling if the stamped contact piece is used,they bend and get out of alignment easily.
if the above doesn't work,let me know,will try to get You thru this !
Spikre