A downlight lighting assembly comprising a plurality of notches and engaging members to ease the alignment and assembly of the components. The downlight lighting assembly comprises an LED chip removably connected to a heatsink with a mixing chamber secured to the heatsink, where securing the mixing chamber to the heatsink provides the compressive force for an LED connector to engage and provide the electrical connection to the LED chip. The heatsink also has a plurality of protrusions on its upper edge to engage a lower wall of a reflector to secure the reflector to the lighting assembly.