Remove and dispose of old HVAC system Install new 4Ton Lennox 2 stage AC/Heat Gas Pack on Enlarge Return to 20x30, High Flow Grille, 18in duct Build small sheet metal Plenum off of package system to connect 18 inch duct, see photos New AC condensation drain line New Gas Flex and sediment trap New Thermostat, Nest Tape and seal duct registers New Service disconnect and electrical whip.