On Our 23b (a '12) it was under the sofa there was a drive nut that would manually operate the slide. The motor was roughly centered and the nut was near it. As I recall there was a wood panel to remove first. I was told during PDI that there wasn't a manual provision but I couldn't buy into that so I tracked it down. Never had to use it but felt better knowing where it was.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks