Public transport
You can walk to the office from the Henk Sneevliet metro station via the directions here on the right. There is also a bus (bus 68), from the metro station to the office. After two stops you are at the office.
Car
You can park your car on the parking deck (Johan Huizingalaan 763A, 1066 VH Amsterdam) across the street at B.1 (See image on the right). From there you can follow the directions on the image on the right.