The LCLS-II injector is a high brightness electron source for injection into a CW superconducting L-band linac to drive an X-ray FEL up to 1 MHz repetition rate. The injector was designed by a collaboration including SLAC, LBNL, Cornell and FERMI labs. An update on the status of the injector will be given including an overview of the injector layout, baseline performance specification, upcoming commissioning work and current results from the APEX prototype injector. Theoretical work to accurately simulate emission from photocathodes will also be presented.