the capstan is fixed to the motor spindle by two small hex
key grub screws.
you need a 1/20" (AF) hex key. this is the smallest of the AF
sizes.
remove the capstan head carefully. be careful not to damage the plastic
disk at the base. this is part of an optical sensor built into the the top
of the motor (i think the hair wires are part of this).
i had trouble removing the head because the grub screws dent the
spindle and burr the metal somewhat.