I would support the floor rather than the edge of the trailer. There are a number of ways to do it. I used wood blocks and axle
stands. Whatwvwe method you use, you need to make sure the weight
is distributed over an area.
is the widest point in the trailer frame. Be prepared to move your blocks after you have your frame separated from the egg. You will probably have to pull your frame forward a bit, then move the block arrangement, then move the frame some more.
Once I had the frame separated from the trailer, I found it helpful to remove the wheels. With wheels removed, you will have more clearance. It might be a good idea to release all the wheel bolts by one half turn. This will make life easier when you go to remove tthe wheels later.