With 2 lines, 2 trees, a come along & a bunch of dog blankets.
However you manage it, get the boat off the trailer. We had a tilt trailer that the boat sort of rolled right off. We had strategically placed dog cushions and dog blankets (we have lots) to not let the boat crash onto the ground. We have 2 really long lines that we use as painters for launching, the bow and stern lines. What used to be the halyard from our 26′ cruising boat and some other lines tied together.
Locate all this between 2 trees, adequately spaced apart. Ours are about 50′ apart. The boat is centered. The lines are tied around the thwart and ran underneath, across the top of the other side. The come-along ratchet is fastened on one tree. Leave plenty of space to ratchet the boat up. The other line will act as a brake, along with a human holding on to it. (I run it behind me around my hips. The strongest part of my skeleton.) As the ratchet works the boat starts to tip up. The person on the brake can assist the boats progress. At anytime in this process before the boat gets all the way vertical the dog beds can be moved around. After the boat is vertical the ratchet is no longer working and the brake is, so the ratchet person can move beds and the brake person can slowly lower the boat to the ground. We put the boat up on blocks, and dog pillows, to keep it off the ground.
The come-along gets an early tighten 
Attaching the come-along the tree 
Blue becomes red when flipped.