Choosing a new spatial reference for an instance (Production Mapping)
You can choose a new spatial reference to use with an instance in the New Instance or the Instance Properties dialog box. You also have the option to choose an existing spatial reference.
Steps:
- Start ArcMap.
 - If you do not have the New Instance dialog box open, right-click an existing instance from the Product Library tree view and choose Properties to open the Instance Properties dialog box.
 - 
 Click the plus sign (+) next to Spatial Reference. 

 - Click the cell next to Use Existing.
 - Click the drop-down arrow that appears and choose False.
 - 
Click the cell next to Base Spatial Reference and click the ellipsis (...) that appears. 
The Spatial Reference Properties dialog box appears.
 - 
Click Select. 
The Browse for Coordinate System dialog box appears.
 - Navigate to the coordinate system you want to use for your area of interest.
 - 
Click Add. 
The Spatial Reference Properties dialog box appears.
 - 
Click OK. 
The New Instance or Instance Properties dialog box appears.
 - Click OK to close the dialog box.
 
6/8/2015