When editing a railing, you can choose a different railing type as well as control the dimensions and settings of posts, rails and newels. You may want to view the parts of a railing before editing railing properties.
To edit railing properties:
Select the railing. If the railing has multiple segments, use Shift+click to select the remaining segments.
Right-click and select Properties, or select Edit > Modify Elements > Properties.
In the Railings dialog, select the Basic tab.
To change the railing type, click on the type you want in the Type area.
To edit the settings of individual railing components, make your changes in parameters window. The available parameters vary depending on the railing type. Clicking a dimension marked with an alphabetical character (a, b, c, etc.) highlights the corresponding dimension in the railing graphic, and vice versa.
Click OK.