First of all, you have to decide the place where you want to build the ladder to access your attic. Find a place where you can easily draw out the ladder and unfold it. Usually, a lobby or walkway is considered as the most appropriate place to build the ladder. However, if you have any other place which is more appropriate, you can build the ladder there.
Then, take a hammer and tap a nail in the ceiling of the attic. The nail should be put in at the starting place of your ladder. Hammer another nail on the other side according to the measurements.
Now, you have to draw a line between the two nails which you tapped in the previous step. You can use a chalk to draw the line. After that, tap all the other nails in their respective places. Cut the ceiling of the attic with the help of a saw. Don’t deviate from the chalk lines, otherwise your ladder will not fit perfectly in the ceiling.
Take the support board and install it in the opening in order to create a minor gap where the attic assembly can rest. Then, pull the stairs in downward direction. Make sure that the assembly is levelled with the stair frame and joists. After setting the stairs, you have to just hand-tight the screws. Make the necessary adjustments and tighten the screws thoroughly.
Pull the attic access ladder to the floor. The ladder should touch the floor. Then, take the bolts and secure the ladder rail with them. If there is no place to insert the bolts, take the drill and make the holes.