Re: braces?
I lifted my 29' Wellcraft Scarab Sport off the trailer using boat stands. They are (typical) a steel stand with a single shaft coming out of it with either a flat pad or a v-shaped pad. The pad is attached to a threaded shaft (exact same thing on the leveling legs of scaffold) that you turn the bold on, raising the pad, and thus the boat. IT's pretty easy to do if you have the stands. Otherwise, you can use a car jack (have had to do that) of appropriate rating. Just make certain to put a good block of wood between the jack and your boat.
You'll have to build up a "stand" (blocks) under it. Basically, you "walk" the boat off the trailer. But them as far in front of your cross members as possible, lift the boat, move the trailer, set it back down, repeat....