There are two ways to obtain the sms database.
1. Obtain from iTunes Backup
The easiest way to find the sms database from your iTunes backup is by simply searching for files containing the string
3d0d7e5fb2ce288813306e4d4636395e047a3d28.
Your computer should find a file named
3d0d7e5fb2ce288813306e4d4636395e047a3d28.mddata or
3d0d7e5fb2ce288813306e4d4636395e047a3d28.mdbackup.
Under Mac OS, the file is located under "
~/Library/Application Support/MobileSync/Backup/[long hex string]/".
For Windows, the directory is "
C:\Documents and Settings\[username]\Application Data\Apple Computer\MobileSync\Backup\[long hex tring]\" (Documents and Settings may vary depending on your language settings).
If you found the file, simply copy it to the root folder of your phones SD card and start the iPhone SMS Import application.
Important: !!This does NOT work if your iTunes backups are encrypted!!
2. Obtain from Jailbroken iPhone
To obtain the sms database from a jailbroken iPhone, SFTP into the phone and copy the file "/var/mobile/Library/SMS/sms.db" to the sd card of your phone and start the iPhone SMS Import application.