Part Modeling > Edit Features > Offset > Offset Surface > To Create an Offset Using Replace
  
To Create an Offset Using Replace
1. Select a solid surface, and click Model > Offset. The Offset tab opens.
2. Select Replace Surface as the type of offset.
3. Click the References tab, click the Replace quilt collector, and select a quilt or datum plane in the model.
4. If you want to keep the selected quilt in the model, select the Keep replace quilt check box on the Options tab.
 
* If you select a datum plane as the replace quilt, the Keep replace quilt check box is unavailable.
5. Click . The offset is created by replacing the solid surface with the quilt.