Why do you need to change the bearing?...it it split and become loose or is it just that it has become too stiff to turn. I am assuming that the 42 has the same bearing as the 435.
Removing it and replacing it is a pain-in-the-butt job and can only be done on the hard
. I recently took sandpaper to mine and it fixed the problem. I had the boat out of the water
and removed the shaft. I created a tool using an 8" piece of scaffolding tube, put a bolt straight through the middle of the tube and secured the bolt in place using nuts and washers, leaving a couple of inches sticking out so that I could attach it to a power drill. I then put 40 grit sticky-backed sandpaper around the tube and sanded the inside of the bearing. It did the trick and my rudder now swings freely. If you need to do the repair in the water
and can drop the rudder out into shallow water you might be able to sand the bushing by hand if you can find a long tube or pole of the right diameter. It wont be perfect but it might free the rudder sufficiently until you next need to haul it and do a proper job.