Transferring Audio Files from a Windows PC:

  1. Using the USB cable, connect your smartphone to your computer
  2. From the home screen, drag the "Notification" bar down and tap "Media device (MTP)"
  3. In the AutoPlay window that opens on your PC, select to browse the device's files and folders
  4. Open the "Phone" storage
  5. Open a different Windows Explorer window and locate the audio files that you wish to transfer from your computer
  6. Copy the files, and paste them on your smartphone's storage. NOTE: there should be a "Ringtone" and "Notifications" folder. Copy the audio files in the proper location, depending on how you want to use them
  7. After the file transfer has ended, click the USB icon from the system tray and safely disconnect your device from your computer

Changing the Phone's Ringtone from the Settings Menu:

  1. Tap the "All apps" icon located on the home screen
  2. Tap "Settings" > "Sound" > "Phone ringtone"
  3. Browse the list of audio files and select the one that you wish to assign
  4. Tap "OK" to confirm your selection

Changing the Ringtone via the Music Player:

  1. From the home screen, tap "All apps"
  2. Open the "Music" application and go to the music library
  3. Sort between "Albums", "Songs", "Artists" and so on
  4. Once you've located the desired song, touch the icon depicting a triangle, associated with the song
  5. Select "Set as phone ringtone"

NOTE: alternatively, you can assign a song that is playing by pressing "Menu" > "Set as phone ringtone"

Changing the Ringtone for a Single Contact:

  1. Tap the "All apps" icon located on the home screen
  2. Open the "People" application
  3. Look for the desired contact, and tap it
  4. Press "Menu", followed by "Set ringtone"
  5. Choose the desired audio file to set as a ringtone
  6. Tap "OK" to confirm

Changing the Volume of Ringtones, Alarms and Notifications:

  1. Tap "All apps" from the home screen
  2. Go to "Settings" > "Sound"
  3. Tap and hold > drag the sliders next to "Ringtone & notifications", "Alarms" and set the volume to a different level
  4. When ready, press "OK" and save the changes

See More: ZTE Radiant (AT&T): Transferring Audio Files and Customizing Ringtones and Notification Sounds