Product review (5 stars): The blower is reverse-threaded! You might not need a new one. Clockwise to loosen.
A few reviews say you can't separate the blower from the motor.  I just fought with it for an hour before looking at the new motor and finding that the threading for the blower blades is reversed.  This means you have to clamp the motor shaft steady (I used vice grips) and turn the blades CLOCKWISE.  After figuring this out,  and loosening what I had already tightened, the blower blades came off just fine.

The motor itself appears to be working just fine.