This publication was developed based on the results of an IAEA coordinated research project (CRP) and will serve as a reference to those potentially involved in conversion of research reactors from high enriched uranium (HEU) to low enriched uranium (LEU). The publication contains comprehensive design and safety analyses for the conversion of miniature neutron source reactors (MNSRs) and includes analyses that were performed by MNSR operating organizations participating in the CRP using data specific to their MNSR. The outcome of this CRP can therefore be used to provide best practice guidelines in preparation for conversion of research reactors by individual research reactor operating organizations, and as a procedural and methodological reference for regulatory bodies and other stakeholders involved in the conversion of research reactors.