Public transport is an excellent means of going to Herengracht 481
From Central Station, the office can be reached using trams 2, 11 or 12. 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,–