There is a constant need for practical and cost-effective software evolution techniques. We have developed a novel evolution methodology that integrates the concepts of features, regression testing, and component-based software engineering (CBSE). Regression test cases are untapped resources, full of information about system features. By exercising each feature with its associated test cases using code profilers, code can be located and refactored to create components. These components are then inserted back into the legacy system, ensuring a working system structure. This methodology is divided into three parts. Part One identifies the source code associated with features that need evolution. Part Two deals with creating components and Part Three measures results. We have validated our approach on the evolution of a real-world legacy system. By applying this methodology, American Financial Systems, Inc. (AFS) has successfully restructured its enterprise legacy system and reduced the costs of future maintenance. In this chapter we show a simple example of this methodology in action.