Stepping the Mast... What's Your Preferred Method?

We need to step the mast while on the trailer before we get to the boatyard (just outside the boatyard) since they don't have a crane. Can you share your best ways to do this? I've thought of a few ways, but would like to hear from the pro's, this will be my first time doing it and plan to do a practice run before heading to the boatyard.

As always, many thanks for your responses,
Christian