A helpful tip for travelers is that, that the street begins from Piazza Carolina. From the Piazza there are steps to ascend from there. Pay attention to the building numbers as we were fooled by the numbering on the neighborhood doors. This I believe is the Spanish Quarter and Vico San Spirito is pedestrian only.
Also if you have baggage do not use the Toledo stop, although it is a lovely walk its too far for carrying luggage. Use the previous Municipio stop, which is closer.