I would do both: Hire the tow truck AND put plywood under the trailer tires.
A professionalize tow truck driver should be able to do the job, but make sure they keep the tongue at a proper height... don't want to nose-dive it or drag the rear of the trailer: the "pull direction" should simulate that of a vehicle.
I would also make sure they pull from the ball hitch part of the trailer. Do not literally put a hook anywhere on the trailer as it might damage the contact point. They should have a ball adapter of sorts that can be placed in the trailer to which then a hook can attach to that adapter.