Motorway exit "La Spezia". Follow the indication for city centre. At the fifth traffic light turn on the left and run along the avanue till the end where you will have to turn right in any case. At the third traffic light turn left, running along the avenue you will find the indication for CINQUE TERRE (about 14 kilometers to Manarola).
Please notice that all Cinque Terre are exclusively pedestrian so reaching Manarola you will have to park or alongside the main road or at the car park situated at the end of the main road before the beginning of the pedestrian zone.
Once parked there are two possibilities to reach "ARPAIU":
The Manarola train station is on GENOVA-ROMA train line.
For your knowledge and time tables please visit official italian railway web site:
Once reached Manarala station, run along the tunnel, turn right and after few meters on the right Via Belvedere begins, run along it and just when you will be in front of the sea on the right you will find "ARPAIU" (the last house in front of the sea). It takes about 4 minutes walking from the train station.