A lighting apparatus for retrofitting an existing luminaire includes a plurality of light emitting diodes (LED) of similar or differing wavelengths arranged and configured in at least one light bar array, a heat sink module thermally coupled to the at least one light bar array, an electronic power module electrically coupled to the at least one light bar array, and a plate coupled to the at least one light bar array, electronic power module and the heat sink module, the plate arranged and configured for coupling to the luminaire to provide quick and easy installation and replacement of the at least one light bar array, heat sink module and electronic power module into and from the luminaire.