NOTE: For instructions on how to back up data on the phone, check this thread.

Restore Contacts from SD Storage:

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

Restore Media Files from SD Storage:

  1. Open “My Files
  2. Tap “SD card” > “Menu
  3. Tap “Edit
  4. Tick the boxes next to the media files you want to restore
  5. Tap “Menu” > “Move” > “Internal storage
  6. Select the desired folder or tap “Create folder
  7. When ready, tap “Move here

Restore Media Files from a Windows PC:

  1. Establish a USB connection between the Android phone and PC
  2. On the phone, enable “Media Device” or “File Transfer” at the prompt or from the Notification area
  3. Open the File Explorer on the computer
  4. Locate the media backup files on the PC
  5. Copy and 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 M20: Restore Contacts and Media Files