The Fluid Science Laboratory (FSL) is a research facility installed in the European Columbus module of the International Space Station. It provides 70+ different optical diagnostics to insertable Experiment Containers (EC). In the first 6 years of its operational life, FSL operations were managed by the Italian Microgravity Advanced Research and Support Center (MARS) following the European User Support and Operations Centre (USOC) concept. In 2013 however it was decided that the Belgian USOC (B.USOC) would take over the operations, with the actual hand-over process starting in spring 2014. This article reports on how this hand-over was executed. It lists the events in a chronological way, and discusses the main challenges encountered by B.USOC. It was found that operational knowledge is difficult to transfer due to the different forums where the information is tracked. A changing ground segment concept complicated the hand-over, which would also have benefited from a consolidated overview of the upcoming activities. Still, B.USOC managed to overcome the difficulties and perform its first onboard FSL operations in April 2015.