Part Modeling > Edit Features > Mirror > To Mirror All the Geometry in a Part
  
To Mirror All the Geometry in a Part
1. Select the part name at the top of the Model Tree.
2. Click Model > Mirror. The Mirror tab opens.
3. Select a mirror plane. Preview geometry of the new Mirror feature is shown in the graphics window.
 
* You can redefine the Mirror plane by clicking any other plane in the graphics window.
4. Click .
 
* To switch the mirror item from part geometry to a surface, plane, or axis, click the References tab. In the Mirror items collector, right-click the part reference and choose Remove from the shortcut menu. Select a plane, surface, or axis to mirror. Alternatively, you can right-click the graphics window and choose Mirror Items Collector. Then you can open the shortcut menu again and click Clear.