This is the first release of a demonstration duplicating the reduction of JWST/NIRCam data described in Ahrer et al. (2022). This reduction steps through the process of creating a transit light curve from raw data of a transit of WASP-39b, observed with NIRCam on July 22, 2022. This transit is part of JWST program ERS 1366 (PIs Batalha, Stevenson, Bean).