Software development is hard and teaching software development is almost as hard. Among the many difficulties that software developers have is that they must deal with long lived systems. Such systems are of necessity handed off from one development team to another, and another, and another, ad infinitum. Each new developer or development team must learn the existing system to the point where they can successfully take over its maintenance. Among the difficulties that we teachers of software developers face is the need to simulate this activity in the classroom, thus to better prepare our students for the work they will do. This paper describes an approach for doing this, and gives practical advice as to how to do it successfully.