First of all inspect the equipment, start of by disconnecting the power to the furnace after that remove the furnace front access doors, then remove furnace inner sheet metal shield. Now remove the knockouts from the furnace cabinet and inner shield pull together the two sections of coil header plate over the coli tubes and put them together with the help supplied screws.
Put the rubber grommets into place next to the coil tubes inside coil header plate holes. Place the rails according to the mechanical diagram that you got with equipment. Slide the coil inside the furnace, resting the drain pan inside the rails. Now align inner shield with coil header plate such that the refrigerant tubes fit all the way through to the knockouts. Now set up the header plates with the help of supplied screws, and in the end replace the furnace front access doors.