Position the hinge rail against the door opening so the top of the hinge rail is at the top of the opening. Hold the rail in place with one hand and mark where the back of the screw holes are located on the opening. Set the hinge rail aside.
Use a drill to pre-drill holes where you made the marks. Insert the inch screws that came with the hinge rail into the predrilled holes, leaving about 1/8 inch of the screw extending out from the opening. Repeat this step for each of the marked locations.
Position the storm door across two saw horses so that the inside of the storm door is facing up.
Attach the hinge rail to the side of the door by sliding the extension from the hinge rail into the notch on the door, and secure it in place with the included screw.
Pre-drill the holes in the door frame at each of the locations on the hinge rail. Insert the screws included with the door into the hinge rail and into the side of the door to finish securing the hinge rail to the door.
Slide the hinge extender into the bottom of the hinge rail.
Carry the Larson storm door to the door opening and position the other side of the hinge rail over the screws that were inserted into the side of the door opening. Use the drill to tighten the screws against the door opening.
Close the storm door and pre-drill the holes where the holes are located on the outside portion of the door hinge. Insert the included screws into the pre-drilled holes.
Install the door cap. Line up the end of the drip cap with the edge of the hinge rail. Check the clearance across the top of the storm door, and secure the door cap in place with a drill and the included screws.
Position the latch rail on the opposite side of the jam. Make sure that the latch rail will line up with the end of the drip cap. Use the drill to secure the latch rail to the door jam with the screws that are included.
Slide the latch rail extender in the bottom of the latch rail so it meets the top of the sill of the door.
Install the handle in the door according to the handle manufacturer's directions.
Slide the rubber weather stripping into the bottom of the storm door expander. Use a side cutter to cut off the excess weather stripping at the end.
Position the expander over the bottom of the storm door. Make sure that the expander touches the top of the door sill. Pre-drill holes into the door and secure the expander in place with the screws that are included with the expander.