Drill a hole into the ceiling where you want your attic stairway to be so you can easily locate the area from in the attic.
Access your attic from the access hole.
Find the location of the drill hole.
Mark out the dimensions of your staircase kit. Make the marks so that the door sits parallel to the joists in the attic.
Cut the joists out of the way for the stair case using a reciprocating saw. Remove all the insulation, then cut through the ceiling with the reciprocating saw to make the rough opening for the stair.
Cut two 2-by-8 pieces of lumber to the size of the rough opening. Nail the 2-by-8s to the side joists with 16d nails. Cut a new joist and hammer it between the two headers to accommodate the size of the stairs.
Secure the drywall on the ceiling beneath your attic with drywall screws into the joists. This prevents the drywall from breaking.
Screw one inch ledgers on the ceiling opening to give the stairs something to sit on. Insert the stair kit into the opening, resting it on the ledgers.
Position the stair well between the joists. Insert shims, small pieces of scrap wood between the stairwell and the joists until the stairs fit snug. Fasten the staircase to the joists with the screws included in the kit.
Remove the ledgers from the ceiling.
Place the molding that comes with the kit over the opening on the ceiling to cover up the screw holes. Attach the molding using the screws that come with the kit. Paint the molding the same color as the walls.