A contemporary software company is often based on mergers and acquisitions resulting in a number of organizational cultures and ways of working within the mother company. The inconsistencies between teams cause friction and ineffectiveness adding to the need of improve one's competitiveness in the ever toughening competitive situation. The streamlining of the operation is often felt the strongest on the operative level. The aim of this paper is to identify the roles and functions of team leaders in implementing a procedural change in software producing business enterprise. The study offers some solutions to the challenges that team leaders face when implementing change in their teams. Here change means new ways of working, including a change of used programming language. This study is a qualitative case study of a large software company that is renewing its software development processes towards component-based-software-engineering (CBSE). The research observes the phenomenon from a software engineering management point of view, and thus combines management with leadership issues.