There is a very well done article, complete with images, done by Jay Grizzell on the Hunter 28.5 website. Also, it may be worth it to have your boat raised by a travelift or similar device in order to remove/reinstall the rudder rather than digging a hole. I removed my rudder this way last year and it worked well. You need someone in the boat and perhaps two others on the ground to control the rudder when it is disconnected.