Get your directions From U-Bahn Uhlandsstaße (2 min walk) find link HERE
From U-Bahn / S-Bahn Zoologischer Garten (5 min walk) find directions HERE
From Alexanderplatz just take S-Bahn 10 min (direction Spandau, Westkreuz or Potsdam) to S-Savignyplatz. From S-Bahn Savignyplatz find link HERE