Public transport is an excellent means of going to Herengracht 481
From Central Station, the office can be reached using trams 1, 2 or 5. Get off the tram at Koningsplein, cross the street/tramrails and walk onto Herengracht on the north/leftside of the canal. You will reach Herengracht 481 after 170 meters.
Alternatively a taxi could be taken from Central Station at a cost of approximately € 15,–