Andrew,
To manually extend the livingroom slide on your coach, you have to vent both of the lines to the control cylinder, and rotate the equalizer shaft with a wrench or manually push the slide. You will need to catch the oil that is displaced. It will help if you use the leveling system to lower the coach on the driver's side and raise the passenger's side, but be very careful if you tilt the coach with vented lines because the slide can move uncontrolled and cause serious injuries.
Gerald