Porta Susa is the closest train station to the department. You can get to the department by walking (it is a 10-minute walk). From the station, turn left and walk along Corso San Martino until Piazza Statuto. At the Piazza, turn right and walk along Via Garibaldi for about 100 meters, until you cross Via Bligny. Turn right and you are in Piazza Arbarello.
 

From Porta Nuova train station

You can reach us by bus (20 minutes), taxi (10 minutes), or by walk (30-40 minutes).

If you take a taxi, it costs about 10 euros.

If you take the bus (about 1 euro), when you exit from the station, cross Corso Vittorio Emanuele and take either bus n. 52 or n. 67. The bus should go westward (to get oriented, remember that river Po is eastward from the station). Piazza Arbarello is the last stop for bus n. 67.  If you take bus n. 52, get off the bus immediately before Via Cernaia, then walk along Corso Siccardi for about 100 metres and you are in Piazza Arbarello.

If you decide to walk, cross Corso Vittorio Emanuele and Piazza Carlo Felice, and you are in Via Roma. Walk along it until you arrive in Piazza Castello (15-20 minutes), then turn left in Via Garibaldi. Go straight ahead until you cross Via Bligny (15-20 minutes), then turn left and you are in Piazza Arbarello.