How to Replace Contents of a Smart Object in Photoshop CS6
When replacing the contents of a Smart Object with new contents in Adobe Photoshop Creative Suite 6, you automatically update all instances of that Smart Object in your document, which can be a real productivity enhancer, especially if you find yourself short on time. Just follow these short steps:
Select the Smart Object layer in the Layers panel.
Choose Layer→Smart Objects→Replace Contents.
In the Place dialog box, locate your new file and click the Place button.
Click OK if you’re presented with a dialog box, and the new contents pop into place, replacing the old contents.Credit: ©iStockphoto.com/LICreate Image #6285730 and DLCreates Image #3342376 and blu 67 Image #3102318
All instances of that Smart Object are also updated in your document.
To replace the contents of a single instance of a Smart Object, you have to make sure that the Smart Object isn’t linked to other Smart Objects. To create an unlinked Smart Object, select the Smart Object instance you want to change, choose Layer→Smart Objects→New Smart Object via Copy. Make your desired replacement and then delete the original Smart Object.