Hi Ellen et al,
Congrats - super that you got it out.
Your method and that in Ken's video, with the special tool he had made, both rely on just adding force (and/or shock) to pull the tube straight out (down). My experience with a few of these really stuck units is it is really helpful to add a rotational force, not just a straight downward pull.
Using a chain wrench around the motor base, with an extension pipe for added torque, let's you rotate the motor (just a bit at a time) on the lower tube. With lots of lubricant and lots of patience and going back and forth it will finally break free without the drama of slamming it up and down against wood blocks or the frustration of the tool sliding down the tube. You do it with the unit fully retracted such that when you torque the motor the rotational forces are taken up by the structure of the hull cavity and the bow thruster's bracket.
It's much like any pipe "stuck" in a socket - turn it back and forth to release it - don't just try to pull it straight out.
Another version of this I just did with good success was to just operate the bow thruster repeatedly to port and then to starboard in short bursts. (Of course, the retaining bolts were out and a hose clamp (Jubilee clip) was in place.) That torqued the motor back and forth with great force and the tube slipped out easily. (Granted, it was not "hard" stuck".) It would likely work best in the water with the added torque resistance of the prop.
Lots of ways to skin a cat.