Functional scenario-based test case generation is an important technique for specification-based testing and it can be fully automated. The vital first step of achieving the automation is automatic transformation from a formal specification into an equivalent functional scenario form from which all functional scenarios are derived. In this paper, we first explain the concepts of the functional scenario form and the functional scenario in the context of a VDM operation specification, and then discuss the techniques for the transformation implemented in a software tool we have built. The techniques for discussion include (1) transformation from compound expressions into predicate expressions, (2) transformation from quantified expressions into non-quantified expressions, (3) replacing implications and equivalences in predicate expressions, (4) transformation from predicate expressions into functional scenario forms, and (5) the derivation of the testing condition from a functional scenario for test case generation. Based on these transformations, the tool can also automatically produce test cases to meet required conditions.