Have the jack cylinders been lubed? You may or may not have grease zerks on the bottom of the jack cylinders. If you have them, put a little grease in them. If you have or don't have zerks, spray some liquid Silicone (not WD-40) on the pistons (Shiny part), then, after telling the jacks to retract, try prying them up a bit. If they are just dry, they will start moving because the springs are what retracts the jacks. You may have to help them retract until you get the Silicone up into the jack cylinders.
Jim and Lynda, (Sophie, Jake, attack trained killer Shi-Tzus :-))
2003 Fleetwood Expedition 38N 2005 Saturn Vue