The objective of this protocol is to provide a set of instructions/ steps to guide ANY NEW USER to generate an open source EI-MS mass spectral library to aid in interpretation of GC-EI-MS spectral data for metabolomics research. Users need to appreciate and acknowledge the efforts of developers who have helped build and released their EI-MS spectral data and associated meta-data for free use and distribution from Mass Bank of North America (MoNA), RIKEN, GOLM Metabolome Database, Cayman, SWGDRUG, and NIST among others.