I could not even turn mine by hand when I got it
Take the fan blade off (small set screw)
Clean the shaft real good
Take the 2 screws out just below the fan on the top of the motor
Tap the shaft through the cover--you may have to put some lube on it. Make sure you note the brushes and brush springs will probably pop out.
Pull the motor winding out of the casing--again, lube the bottom and it should tap out.
Clean the upper and lower shafts that go through the case, clean the bushing on the top and bottom that the shaft goes through. Clean the inside of the case.
Make sure the shafts go back into the bushings nicely on both ends.
Put the brush springs back in, and the brushes. You can hold the brushes in with your fingers by the wires.
Lube the bushings with grease
Put the motor in the top of the motor case to hold the brushes
put the bottom of the case on, and put the 2 screws back in.
touch the wires to the + and - of a battery. I bet it spiins like crazy.
Your motor is repaired