Are you sure the motor is faulty, have never had to replace a Neff dryer motor in 35 years repairing Neff appliances. If the motor is free to turn but just buzzes when energised the most likely fault is the capacitor for the motor. Come back with more info. If you do need to replace the motor you need to remove the right side panel, remove the spring on the tension pulley(pull out the plastic clip holding the bottom end of it ) remove the fan blade covers, pull out the plastic clamp securing the motor.
Kenjo, February 2014