as you don't have the kind of
"jack" I did

the way to do it is to block under the floor, jack one end then the other just enough to get some planks under longer than the width, then jack them from outside until you've got the body high enough to roll the chassis out .... have to block between the planks and the body to clear the quarters/steps, but it's not hard for one person to do it alone that way
Bill