You can change the depth value and modify the top and base of the blend. 
- In the drawing area, select the blend. 
- If you are in the project environment: - On the Modify | <Element> tab Mode panel, click Mode panel, click (Edit Family). (Edit Family).
- In the Family Editor, select the blend in the drawing area again. 
 
- On the Options Bar, enter a value in the Depth text box to change depth of the blend. 
- On the Modify | Blend tab Edit Blend panel, select an editing option: Edit Blend panel, select an editing option:- Click  (Edit Top) to edit the top boundary of the blend. (Edit Top) to edit the top boundary of the blend.
- Click  (Edit Base) to edit the base boundary of the blend. (Edit Base) to edit the base boundary of the blend.
 
- On the Properties palette, change the visibility, material, or subcategory of the blend, as desired. 
- To change the blend to a solid or a void, under Identity Data, for Solid/Void, select Solid or Void. 
- Click Apply. 
- On the Modify | Edit Blend Top Boundary tab or Edit Blend Base Boundary tab, click Mode panel  (Edit Vertices), and edit the blend vertices. (Edit Vertices), and edit the blend vertices.
- On the Mode panel, click  (Finish Edit Mode). (Finish Edit Mode).