Here's a few details
We use vertical lift boat lifts up here and that works quite well for changing the line. Another option would be to borrow a trailer from someone with a shoal keel. Some examples are Seaward 25, Compact 25, or Catalina 25 swing keel. I secure a line about 2/3 back from the front of the centerboard going up on both sides of the boat. This carries the majority of the weight while removing and installing the centerboard. There is a 1/2" bolt underneath the inspection cover behind the compression post below the table that holds the assembly in place. It most likely has a fair amount of 5200 smeared around it that must be cut off. Remove this bolt while someone is holding the board from below. The pivot assembly will now come down so you can change the line.For re-assembly, run the new line down the tube around the turning block in the assembly and into the centerboard with an end knot. Have a person hold the centerboard assembly in place (again, using a line underneath the boat helps take much of the weight off the portion the person is holding up). Use of a punch to line up the holes helps make the insertion of the bolt much easier. Once the bolt has started, but still loose, have the person below hold the assembly up tight while you work 5200 underneath the bolt head & washer before tightening the bolt. Add a little more 5200 around the bolt head, washer area when finished to ensure no leaks (This area is slightly below the water level when the boat is filled with water ballast, so it's important to have a good seal.