there is a bus (costs about eu3) from the train station at Pompeii or Orcelano that takes you to the trail ticket office. cost for trail is eu10. trail is about 300 m up the road from ticket office and you need to have those tickets to start the trail. Don't take a taxi. and don't take a taxi going down either. these stop a bit further down at parking lot and don't always go all the way back to a train station. tickets for bus are bought on board. schedule for bus going back is not frequent and remains a mystery.