The report breaks down best practices and guidelines for conducting case retrofits by project stage, from initial planning through project completion and system monitoring. Namely, the guide highlights the following areas of the process: retrofit planning, case modification and door retrofit, refrigeration-system reconfiguration, system performance evaluation, and monitoring and follow-up. This guide also provides background information on display door retrofits and offers specific technical guidance in key areas of the process where sources have suggested that errors may commonly occur. However, due to variations within installed systems, the applicability of sections of this guidance to a given refrigeration system or display case may vary between projects. For this reason, retrofit projects should always be overseen by a qualified refrigeration engineer or contractor.