I have removed a trailer from smaller hulls several times. The approach is the same for larger hulls but the actual job is a lot scarier the bigger the load.
Even small hulls can pose significant risks to you should loads shift.
To do it correct for a small hull, you need at a minimum 2 boat stands (cement blocks are too scary), a bottle jack, a steel channel or flat plate and preferably a keel stand or as a substitute 4x4 or 6x6 cribbing.
You put the boat stands under the rear outer ends of the hull and tighten. You need to take some load off of the rollers or bunks and to do so the safest way is to jack up the trailer at the rear a little bit, one side at a time, and re tighten the jack stands. When you have some of the load off, it's time to jack up the front keel. Using the bottom jack, cribbing as needed and the steel plate perhaps with a piece of carpet on it, jack up the hull till the trailer is free. Extend the keel stand or install cribbing. Pull the trailer forward until a cross member bumps into the keel cribbing. Jack up the keel (you probably will have to move the jack, remove and relocated the cribbing aft past the first cross member or axle. pull the trailer again and repeat as necessary. It may take 3 to 5 repetitions to get the trailer cross members cleared. Go slowly and be aware that the hull and/or trailer may shift. Try not to be under anything that might crush you if the boat slips off the cribbing or the stands.
Instead of a bottle jack it is also possible to use a garage hydraulic floor jack. Since those have a much larger plate on top, you can use a 4x4 or a 2by piece of lumber instead of the steel channel or plate.
As I mentioned, the process is scary and honestly for me , not something I want to do again.Be careful with floor jacks since either the load ot the jack will move sideways as it raises and lowers.
For the last several years, I have taken a different approach. I jack up the boat on the trailer lifting the trailer from its frame about a foot and use boat stands and a keel stand to hold the boat at that height while I hen lower the trailer. The hull is in effect suspended over the trailer and there is enough (still a pain to work though) space to sand scrape and paint everything except where the boat stands support the hull. Those areas get worked on after the majority of the hull is finished and the boat is lowered back onto the trailer.
The up side for this approach is that should the hull slip off the stands, it falls onto the trailer. When the hull is in the raised position you should block the trailer frame in the rear so that should the load fall down the frame will not crush you when the springs get compressed if you are under the hull. Avoid having you arms or hands between the rollers or bunks and the hull.
The second approach can be scary too but a lot less than the trailer removal operation.
