Bus line 113(maybe from Altona S-Bahn-station): station "Schulweg": You get off the bus at the major intersection Osterstraße/Schulweg. Enter the Osterstraße in direction east towards Bundesstraße. The third street on the left is Bismarckstraße.
Or bus line 182: station "Kaiser-Friedrich-Ufer". After you go a bit westward and cross the bridge above the Isebekkanal, turn right into the Bismarckstr. The Elbe 76 is on the left side after 200 m, at the intersection with Göbenstraße.
Or bus line 181: station "Bismarckstraße", at the intersection between Bismarckstraße and Mansteinstraße/Bogenstraße. After you get off the bus, enter the Bismarckstraße direction southwest (if you go northeast instead you will meet the people coming from the "Hoheluftbrücke" subway station somewhere in the middle :->).
You can take the Buses 181 and 182 from the subway station "Schlump" (Subway lines U2 (red) and U3 (yellow)). After you emerge from the underground, leave the station left hand (there's a Kebab shop on the right side) and you see directly the bus stop for 181 and 182.
Subway line U3 (yellow): station "Hoheluftbrücke". When you leave the station, turn left, ignore the MacDonalds and cross the bridge. The first street left is the Bismarckstraße. The Elbe 76 is on the right side after 500 m.