Research on science education in Africa shows many teachers continue to use traditional lecture methods even when curriculum favours more student-centred approaches. This paper explores science teacher professional learning as a means to realise practice change at a crucial time of curriculum reform in Ghana. The study was a qualitative formative intervention involving six junior high schools. The aim was to explore possibilities of aligning the intended curriculum with the implemented curriculum, focusing on student-centred aspects. One teacher from each school joined six Change Laboratory sessions over three months. Transcripts from these were complemented by two interviews with each teacher, and 18 lesson observations early, during and after the Change Laboratory. Teachers' practices changed in four key areas that strengthened student-centred pedagogy: use of questions, assessment, teaching beyond the classroom and designing a range of activities. Pedagogies that were initially seen by participants as impossible became viable as the Change Laboratory helped teachers see new ways to implement the intended curriculum despite challenging conditions. This paper contributes to knowledge of science education in relation to curriculum reform, showing how a Change Laboratory can support feasible change at the edge of what is possible in an African context.