Do you have room at your house, or a friends to store the boat while you work on the trailer? I just finished a "boat off" trailer restoration. It came out very well, but is very time intensive if you want a good finish. You can paint or powdercoat depending on you budget. I painted, used PPG's Concept/DCC Eurothane, 5 quarts total.
$165.00 per gallon not counting reducer or hardner, and don't forget primer. Spend plenty of time on prep, it pays off in the end. As far as taking the boat off, I did it myself, with a jack, a Shitload of 4x8 block, and half a saturday. Just kept lifting, blocking, and moving the trailer forward.