To use the Legrand (G4010B) 4000 Raceway Surface Metal Blank End Fitting, first ensure your raceway system is installed and ready for finishing. Begin by measuring the open end of the raceway to ensure a proper fit for the blank end fitting. Next, slide the blank end fitting onto the open end of the raceway, making sure it aligns with the edges. Secure the fitting in place using the appropriate fasteners or clips, depending on your raceway system's design. Finally, check the fitting for a tight seal, ensuring no gaps are present to maintain the integrity and safety of the electrical system.