Kneel at the top of the trap door, facing away from the staircase. Place any objects you want to bring down from the attic in front of you.
Slide one of your feet backward and down onto the first step.
Grip a nearby wooden beam or a non-moving part of the top of the staircase to steady yourself.
Slide your other foot backward and down onto the second step from the top.
Continue climbing down backward one step at a time until you're halfway down the staircase. Place any objects you need to bring down from the attic onto the top step of the staircase. If possible, hand the objects to a second person on the ground or just drop them to the floor if they're light and won't break.
Climb down the rest of steps. Move any objects you are bringing down one step at a time.
Fold up the staircase, starting from the end, and push it back up into the trap door space.