I guess my original reply got lost in the clean up of the several identical posts on different sections.
The rig you describe might have TIP OUTS not slide outs.
A tip out has a curved or sloped roof and is designed to be picked up from the outside bottom and tips into the rig - pivoting on a big hinge along the bottom joint. The tip out lays down inside the rig for transport. You will likely need to provide a tarp or sheet of plywood to cover the hole for transport.
Look under the slide outs. If you see gearing and supports - it is a slide out. If you see just a flat surface - it is likely a tip out.
If it is really a slide out, the manual crank is accessed from the opposite side of the trailer as the slide out.