One of the most vital techniques in the context of software product line (SPL) evolution is refactoring – extracting and refining reusable assets and improving SPL architecture in such a way that the behavior of existing products remains unchanged. We extend the idea of SPL refactoring to technical documentation because reuse techniques could effectively be applied to this area and reusable assets evolve and should be maintained. Various XML-based technologies for documentation development are widely spread today, and XML-specifications appear to be a good field for formal transformations. We base our research on the DocLine technology; the main goal of which is to introduce adaptive reuse into documentation development. We define a model of refactoring-based documentation development process, a set of refactoring operations, and describe their implementation in the DocLine toolset. Also, we present an experiment in which we applied the proposed approach to the documentation of a telecommunication systems SPL.