I had to move my shed, but it was only about 20 feet. We jacked up the rear and pushed a couple of 2x10's under the runners. I screwed a piece of plywood to the other side, then used the F250 to push it across the yard.

If you have 4x4's underneath, they will slide if you put a couple of 2x8's or 2x10's under them.
I'd try making a ramp from the shed to the trailer, supporting it a couple of places in the middle,
then either winching or pushing it up onto the trailer.