There is a good chance a stuck stepper motor can be repaired. The motor’s case is composed of two pieces, which tend to go apart and the axle with stationary magnet gets stuck against the surrounding case. The motor can be removed from the disk drive. It is a good idea to mark the position of the motor against the drive housing for reinstallation. The wires going to the motor most likely need to be cut and later soldered back.
After the motor is removed from the drive, the axle with the magnet can be removed from the housing by cutting off the back label and removing a front washer.
After cleaning and fixing any issues with the housing, reinstallation is in the reverse steps. It is probable that the drive will need recalibration. It can be done following this instruction. I have not done that, since my drive just worked fine after reassembly.