You can change a deck’s railing type by making a selection on the Accessories property page.
To change a deck’s railing style:
Select the deck by clicking on one of its edges.
Right-click and select Properties, or select Edit > Modify Elements > Properties.
In the Decks dialog, select the Accessories tab.
In the Railings area, click the Select button.
Select the desired railing type from the catalog.
Click OK.