NOTE: You can check this thread for a guide on how to back up data on the phone.

Restore Contacts from SD Storage:

  1. Launch “Contacts
  2. Tap “Menu” > “Settings
  3. Tap “Contacts to display
  4. Select “All contacts” and tap “Import/Export contacts
  5. Tap “Import from SD card” > “OK

Restore Media Files from SD Storage:

  1. Launch “My Files
  2. Access “SD Card
  3. Tap “Menu” > “Edit
  4. Tick the boxes associated with the media files you want to restore
  5. Tap “Menu” > “Move” > “Internal storage
  6. Tap “Move here” > “Create folder
  7. Select the desired folder and tap “move here

Restore Media Files from a Windows PC:

  1. Connect the Android phone to the PC via USB
  2. On the phone, enable “Media device” / “File Transfer” at the prompt or form the Notification shade
  3. Open the File Explorer on the PC
  4. Locate the media backup files on the PC storage and copy them
  5. Paste the files to the phone storage, preferably in the folders from where they originate
  6. Once done, eject the phone storage and safely disconnect the device from the USB cord

See More: Samsung Galaxy A9 Star Pro: Restore Contacts and Media Files