Are you 100% sure the livewell lines aren't leaking? Put a plug in the livewell drain hole in the transom, and try again? Where are you located? What size boat is it?
To get my boat off the trailer I used my trailer tongue jack. Crank it all the way down as far as it will go, then block the transom solid. Now, crank the tongue jack all the way up and the transom will lift off the trailer. Once you have the jack all the way up, block under the keel at the bow, and let the jack down enough that you can see the whole hull. I have done this several times to replace my trailer bunks over the years, and once to paint the boat. It works, just make sure you have it blocked up good and solid.
S.