In economics numerical approaches are increasingly used for the analysis of dynamic phenomena of economic development since almost 30 years. The first generation of simulation models was rather focused on stylized empirical phenomena. With the emergence of agent-based modelling the last 10 years, however, the trade-off between simplicity and abstracting in modelling, and taking into account the complexity of the socio-economic reality has been enhanced to a large extent. This paper serves as a basic instruction on how to model qualitative change using an agent-based modelling procedure. The necessity to focus on qualitative change is discussed, agent-based modelling is explained and finally an example is given to show the basic simplicity in modelling.