First of all, connect your iPhone to the PC and run the program directly. You will see the interface as below. Then, go into DFU mode to let the program to scan your iPhone.To allow the program scanning your iPhone, you need to let your iPhone goes into DFU mode (no harm to your device). Follow the steps as below (or the image above): click the Start button of your iPhone; simultaneously pressing Power and Home button for 10 seconds; release Power but still pressing on Home for another 10 seconds. After doing like this, your iPhone will go into the mode of DFU and the app can scan your files.
Preview the list of messages and choose the ones you want to recover.You can see the entire files list on the left of this program, including camera roll, photo stream, contacts, messages, and so on. Now choose the category of Messages, find the SMS you want to recover, and press down the button of Recover to save them on your PC.
If you have backuped it before, you can recover SMS from iTunes backup. Launch the program and switch it to the option of Recover from iTunes Backup Files. You can see your entire iTunes backup on the list. Choose the one for you and start to scan. Preview all the messages and recover the ones you need. Just like directly recover from devices, you can see the list on the left. Now you can choose the category of messages and find the ones you want to recover. Click the button of “Recover” to accomplish the work.