There might be another way, but you will need a lot of time energy and patience. The bow thruster on my SM jammed solid a few years ago in Mexico and it would not move. After several days trying to get it out, It became obvious that any more dropping or hammering was going to damage the boat.
So, I removed it complete with the motor stuck to the shaft from the inside of the boat. It took a full three days, dawn to dusk to remove and replace.
The complete unit weighs around 80lbs . You need to be really careful to mark all the electrical cables as on the SM there were lots of black ones!
If you consider going this way, be sure that all power is isolated.
The position of the limit switches is really important to ensure that the bow thruster will retract properly when serviced and replaced.
It is a nightmare of a job but it can be done.
When we finally got it out it couldn't be pulled or pressed apart, so it had to heated to white hot before it broke apart.
Bill has Kindly renewed my membership in the hope that this message may be of some help to you.
Former owner Seafever of Cuan