Some photos would help.
How does the shaft look? If the coupling is a rusted ball, you may not be able to get it off the shaft. That may mean cutting the shaft to get it all out.
But you need to make sure you can get a new shaft back In Without having to drop the rudder or raising the engine (unless you are prepared to do that).
Not familiar with your boat, so don’t know how the Cutlass is mounted. On my boat, an O’Day 322, the cutlass is in a strut. I had to press it out with a tool my bro-in-law made for me.
Here are some videos of my shaft removal and replacement project:
Strut bearing removal
Coupling removal
Shaft removal
Shaft installation
Post a pic of your cutlass bearing so we can see how/where it is mounted on your boat.
Greg