Before you invest in boat stands...
Try raising the stern just aft of the centerboard using a floor jack and some blocks of wood. Additionally, you could probably drag the boat off the trailer and roll it over. This is just a 19 ft boat with no ballast, right?
You could also use a shop crane (engine lift). I lifted my C22 off the trailer using a shop crane with a tow strap run under the stern forward and wrapped around the swing keel and back to the crane. Any anchor point to keel the strap under the stern will work.
All of these solutions are less expensive than boat stands.