Bobby -
While we don't have the exact year and model, it might be close enough to let you know where you might want to look.
Our manual override is located, of course, underneath the unit on the "passenger" side. There is a small partial cut-out in the black coroplast underbelly about 8 in sq.
It is found approximately 2 ft in from the side and about 1 foot in front of the front, rear tire.
This cut out is cut on 3 sides and held in place by black, plastic ties. If you remove the ties, the flap drops down revealing the crank mechanism and motor. You will need a 3/4 in (I think) socket to fit over the nut and a rachet.
Have a look in that location and see if you have such a cut out. We haven't had to use the manual crank but if we do, you can bet it will be cold and muddy!
For proper instructions about cranking it by hand and servicing precautions, you can refer to the Lippert slide manual. Here is their website ....
www.lci1.com
You can find the appropriate Lippert component and download the Operation and Service Manual.
Hope this helps.