This Project Handbook describes how the management procedures and processes are defined and implemented within the TREX project. This includes the CoE governance structure and associated infrastructure, as well as the project operational guidelines. Management activities will be monitored within Work Package 8. Some sections are reused from the original proposal. The Handbook is a living document in that it will be updated as required throughout the project should possible improvements be identified, or an unforeseen risk occurs. This report is divided into multiple chapters. In Chapter 2, an overview of the project and the key reporting periods to the European Commission are provided, as well as a summary of the milestones and deliverables. Chapter 3 describes the CoE Governance structure, the details of the associated infrastructure, and the different roles and associated responsibilities of the partners. The operational Guidelines are summarised in Chapter 4: these cover the way of reporting, the risk management procedure, the decision-making, and the conflict of resolution procedure, as well as the dissemination procedure. The report is concluded in Chapter 5.