Thought I'd mentioned this as I've seen many solutions that are way too difficult and/or dangerous.
Just finished replacing the board on Teliki (split ream repair) and it took 30 minutes from start to finish.
I start by cutting a dozen pieces of 2 X 4 about a foot long.
Then I jack the boat up about a foot and a half with a floor jack . The jack is placed about two in front of the centerboard opening. Release the hold down on your bow eye and anywhere else before jacking. The front of the trailer will also lift as you do this.
Once jacked up, get someone to stand of the trailer tongue. This will pivot the trailer down on the rear bunk and open up a foot of space at the front bunk.
Insert your 2 X 4 blocks between the front of the hull and trailer as well as between the front bunks and hull. This blocks the boat in position at two places ( as well as the jack) providing safety from it falling. If it did fall, it's only a foot.
Here is a pic of it blocked - 10 minutes invested so far.

I replaced the uphaul with 3/8 yacht braid. A washer was bent to match the opening and prevent the knot from leveraging the centerboard seam open. A double stopper knot on the line fits perfectly in the hole. Don't loop the line through the hole and knot it externally. This will prevent the board from being pulled fully up and it will "clunk" at anchor and drive you nuts. I also beveled the entry hole for the line to reduce chafe (see the second pic).


My 26S has the external access to the pivot and retainer bolts - and can be a PITA to get these installed through that 2 inch opening on the hull bottom.
To do this easily, use electrical tape to hold the but against the washer. The box end wrench will slip over the nut and also stay in place (tape will stretch).
You can then position the whole thing by sighting through the screw hole - when lined up, insert screw and tighten.

Easy, peazy - no cradle, oil drums, slings, oak trees involved and the boat stays on the trailer.
Oh - there is a variant of this for painting the hull where the bunks contact it. Winch the boat forward as you jack it. This will pull the trailer forward under the boat about a foot and expose what used to be under the banks. No blocking or anything and the boat (at least ours) returned to its proper place on the bunks as soon as the winch was released. We use Liquid Rollers on the bunks which make this easy (no "Mac bump" required either).
Chris
Just finished replacing the board on Teliki (split ream repair) and it took 30 minutes from start to finish.
I start by cutting a dozen pieces of 2 X 4 about a foot long.
Then I jack the boat up about a foot and a half with a floor jack . The jack is placed about two in front of the centerboard opening. Release the hold down on your bow eye and anywhere else before jacking. The front of the trailer will also lift as you do this.
Once jacked up, get someone to stand of the trailer tongue. This will pivot the trailer down on the rear bunk and open up a foot of space at the front bunk.
Insert your 2 X 4 blocks between the front of the hull and trailer as well as between the front bunks and hull. This blocks the boat in position at two places ( as well as the jack) providing safety from it falling. If it did fall, it's only a foot.
Here is a pic of it blocked - 10 minutes invested so far.

I replaced the uphaul with 3/8 yacht braid. A washer was bent to match the opening and prevent the knot from leveraging the centerboard seam open. A double stopper knot on the line fits perfectly in the hole. Don't loop the line through the hole and knot it externally. This will prevent the board from being pulled fully up and it will "clunk" at anchor and drive you nuts. I also beveled the entry hole for the line to reduce chafe (see the second pic).


My 26S has the external access to the pivot and retainer bolts - and can be a PITA to get these installed through that 2 inch opening on the hull bottom.
To do this easily, use electrical tape to hold the but against the washer. The box end wrench will slip over the nut and also stay in place (tape will stretch).
You can then position the whole thing by sighting through the screw hole - when lined up, insert screw and tighten.

Easy, peazy - no cradle, oil drums, slings, oak trees involved and the boat stays on the trailer.
Oh - there is a variant of this for painting the hull where the bunks contact it. Winch the boat forward as you jack it. This will pull the trailer forward under the boat about a foot and expose what used to be under the banks. No blocking or anything and the boat (at least ours) returned to its proper place on the bunks as soon as the winch was released. We use Liquid Rollers on the bunks which make this easy (no "Mac bump" required either).
Chris