You can move a deck staircase by clicking and dragging it along the deck edge. Note that you can’t move deck stairs away from the deck, but you can move them to another deck edge. Also, the opening in the deck railing adjusts with the move of the deck stairs.
To move a staircase by clicking and dragging:
Click on the staircase to select it.
Hover your pointer over the center
grab handle to display the Move cursor.
Click and drag the staircase along the deck edge to move it.
Release your mouse button.