From Bonn central station (Bonn Hbf):

Take the bus number 603 (Bechlinghoven), 607 (Ramersdorf), 608 (Gielgen) or 609 (Gielgen) and ride past Konrad-Adenauer-Platz to the bus stop „Doktor-Weis-Platz“. When you get there, go in the direction of the roundabout and take a left turn into Obere Wilhelmstraße. You can also take the Straßenbahnlinie/tram 62 (in the direction of Oberkassel) to get there. Then, go to the house number 29 and through the driveway. Turn to the left, go downstairs and ring for the GAP at the door.

From Beueler station (Beueler Bahnhof):

With your back turned to the station building go to your right and follow the tram lines. Those will guide you into the Obere Wilhelmstraße. You can also take the Straßenbahnlinie/tram 62 (in the direction of Oberkassel) to get there. Then go to house number 29 and through the driveway. Turn to the left, go downstairs and ring for the GAP at the door.