To get to the CB on a DS, you need to put the boat on its side. That's done by "launching" it from the trailer to the ground (grass/carpet, something a bit soft). Just like you would launch it into the water if you don't fully immerse your trailer. It's easier, perhaps, with a trailer that can tilt. If not, you may need to tilt the trailer.
To get the boat on its side takes 3-4 people; or you can raise your mast and use a halyard to pull it over (that one works single-handed). You can then extend the CB.

Once you pull the CB handle (there are three screws), the CB on a DS1 comes out.

The most difficult part about the repair is finding some suitable material for a shim. I finally decided to hammer flat a copper or bronze washer, because the handle and the hole are bronze, and therefore copper or bronze should present the least issue wrt dissimilar metals.
Make sure you mark where the handle should be (90 degrees) so you can check that the shim end up in the correct position --- before reassembling and righting your boat.