As others have said, changing the cutlass bearing can be done without pulling the shaft (or dealing with the coupling, or dropping the rudder), but you need some tools to press the bearing out of the strut. You can make the parts you need, but I had my brother-in-law make mine in his machine shop.
The guy that bought my old boat made his own and we were able to to press the old bearing out and the new one in.
Here is my set up.
Greg