Living labs are an extremely attractive open innovation landscape for collaborative research and development activities targeting the complexity of today’s societal challenges. However, although there is plenty of support for collaboration, we still lack clear guidelines to direct transdisciplinary stakeholder networks of academics and practitioners through collaboration processes in the living lab ecosystem. In other words, we lack answers to the question of “how to collaborate?” In the present paper we propose a conceptual framework defining relevant stages to initiate and facilitate transdisciplinary collaboration processes. We base our framework on collaboration challenges described in the literature, specifically the need for stakeholder alignment, as well as challenges experienced in practice, which we report through exploratory case studies. In the proposed conceptual framework, we advocate the application of co-creation methods, both at the level of the living lab (macro) and in projects (meso) within the living lab, in order to define, with all involved parties and stakeholders, the scope and strategy of the living lab and to facilitate stakeholder alignment. Additionally, we integrate an iterative approach and a feedback loop in order to account for the dynamic nature of the collaboration process and to enable reflection and evaluation.