This technical note outlines the inlet septum replacement procedure for the CAP injector assembly (Item #: N6100007, 120V; N6100137, 230V) for the Clarus® 500/580, & 600/680 GC platforms. The injector assembly is designed for quick access to the inlet septum for routine maintenance and easy integration into daily workflows. Figure 1 provides a diagram of the injector assembly as viewed from the top of the instrument chassis, highlighting placement of the septum cap (Item #: N6100153) containing the septum within.