To access the full version of the ScienceDirect database, users must first register for a free account using a temporary ID and password provided by the Brunswick Community College Library. The document then provides step-by-step instructions on how to register for an account, sign in, and search the ScienceDirect database to find full-text journal articles and book chapters. Users can perform targeted searches by keyword, subject area, article type, and date range to find the most relevant results.