A number of people have contributed articles on this topic.
Rudder shaft Corrosion on Canopus. Tim's photos show the crevice corrosion these rudders are subject to.
Removing the Rudder. Rick Crane on Sea Crane has written on the methods used to remove and replace the rudder on a KP44.
Rebuilding the rudder on Persistence. Tom and Wendy Hoffman's photo-essay on how they rebuilt their ship's rudder. Includes photos of their shaft seal replacement.
Rebuilding The Rudder Greg Rodgers on KP44 Second Sally tells you how.
Rudder Failure and Repair. Britt Finley on KP44 Restless exhibits a bit of seamanship when his rudder fails off near Fiji.
Totally Rebuilding The Rudder on KP44 Deo Volenteby Raul the Pig
A related issue, bow seam voids, is discussed by two KP44 owners in this next article: