If you leave the boat strapped to the trailer, you can use the winch that most of us have mounted on the front trailer mast support. After the spinnaker halyard is rigged and the wires all connected, I hook the winch to a trapeze line and have someone start to crank in the winch while I support the mast on the trailer...it's still a good idea to give some upward push - especially when the mast is down low and the angle to the winch is shallow...but it helps to take a lot of the effort out of the heave-ho. BE SURE to leave the boat strapped firmly to the trailer.

Alternatively, someone can stand on the front beam holding two trapeze lines and lean back to help take some of the load off the person pushing the mast. This is a little risky and shouldn't be done on the trailer (so they don't have far to fall if a slip is made).