How could attackers storm a stair-defended castle?

How could attackers storm a castle when its stairways favored the defenders?

Archers and scaling ladders could put troops above the defenders, creating pressure from both directions.

Archers and scaling ladders offered ways to bypass the protected ascent. If troops reached the upper level or walls, they could descend on the defenders while the original assault continued from below. The tactic turned a one-directional defensive advantage into a fight on two fronts.