In a stair assembly, you can convert a common run or an automatic landing to a sketched run or landing component. 
 After converting the component, you can then use the sketch tools to modify the design as needed. 
Important: When you convert a component to a sketch, it no longer retains the automatic relationship to other components. For example, if you convert a landing to a sketch, then change the run width, the landing shape will not change automatically. Sketched components must be updated manually. 
- Select the component stair, and on the Edit panel, click  (Edit Stairs). (Edit Stairs).
- Select the run or automatic landing component, and on the Tools menu, click  (Convert to Sketch-Based). (Convert to Sketch-Based).
- At the confirmation prompt, click Close. Note: After you convert a common component to a sketch-based component, you cannot convert it back. It is now a sketched component. Use the Undo tool to return to the common component, if desired.  
- Edit the sketch as required.