Many organizations use business process management to manage and model their processes. Currently, flow-based process formalisms, such as BPMN, are considered the standard for modeling processes. However, recent literature describes several limitations of this type of formalism that can be solved by adopting a constraint-based formalism. To preserve economic investments in existing process models, transformation activities needed to be limited. This paper presents a methodical approach for performing the tedious parts of process model transformation. Executing the method results in correctly transformed process models and reduces the effort required for converting the process models.