I'd stop in the local Sheriff's office and ask to speak with someone about the situation if the deadline doesn't work. Chances are, you are not the first to have an issue with this person/place.
After that, I'd just hire someone else to lift it off the trailer and place it exactly where it sits, on blocks. You don't want to risk damaging it by a crude method of removing it from the trailer. He could come after you legally or vengefully if something like that happens.
You also don't want to place it in the water. If it's not seaworthy, they are going to come after the one who launched it and the owner. You don't want to be a part of that mess either.