To Nemo Acc:
As you walk out the front of the Central Station in Amsterdam, you should see on your left the Sent-Nicolas Cathedral - walk there, it is about 150 meters walk. As you are there, follow same street side along ( Prins Hendrikkade ) to the number 133, another 300 meters. That is not a hotel, is a normal Amsterdam House, so please find the door bell for Nemo ACC, and one of the greeters will be there for you.
The second location is in 2 minuets walk from there...