Getting SN off trailer.

Whats the best way toget a SN off a trailer to sand blast & paint the trailer? I know the SN needs to be blocked up some how?

Still, Here's the way Alan did it that Greg mentioned. It is a fairly long thread and I finally found it:

"As for putting the boat on stands I used my engine hoist to lift the back, placed stands under it then went to the front with the hoist and slid the trailer out. A little tricky by myself but it worked."

However, if you don't have a engine hoist, Here's the method we used for storage without trailers and before fork lifs/racks when I was working at a marina.

Lower the trailer tongue as far as posible.
Block under the transom of the boat at both corners.
Raise the tongue with the jack stand and block under the keel at about the helm.
When you lower the tongue, the boat will now be on the blocks.
Now, using a hydraulic bottle jack under the keel again jack in a position as far forward from a trailer frame cross member as possible.
Jack and pull the trailer forward.
Rejack and move the keel blocking and move the trailer again.
you may need to do this several time before the trailer is out.