If you are arriving in Hamburg in a regional or national train going all the way to Hamburg-Altona, please stay in the train and get off at the Dammtor stop. If you are using mass transit, the S31, S21 and S11 lines also stop at Dammtor. From there it's a ten-minute walk up Rothenbaumchaussee to Binderstrasse, just before the Völkerkundemuseum. Turn right into Binderstrasse and walk one block to Feldbrunnenstrasse.
If you use the U1 line from the Hauptbahnhof Süd stop (at the main station), get off at the Hallerstrasse stop and exit the station, following directions to the Völkerkunde-Museum. Walk down Rothenbaumchaussee to the museum, continue walking past it and turn left into Binderstrasse. Walking one block will bring you to Feldbrunnenstrasse and you will see the UIL on the opposite corner. This is a five-minute walk.
You can also take a taxi from the main train station to Feldbrunnenstrasse.