In this streamlined workflow, you select a component, save a copy of that component to disk, and replace the selected component within the assembly with the newly created copy while maintaining all assembly constraints.
On the ribbon, click Assemble tab Productivity panel
Save and Replace .
Click to select a component.
Optionally, in the Create Part or Create Assembly dialog box, modify the name for the copied component or sub-assembly.
Click Save to save a copy of the selected file and replace the selected file with the newly saved copy.