Figured it out. When you connect the phone (lock screen unlocked) the phone gives you a notice of a USB connection and asks if you want to charge the phone or transfer files (choose transfer files) and you can access the phone on a PC.

"Enable “Media device” / “File Transfer” at the prompt or from the “Notification” area"

I receive no prompt. The phone is charging but no prompts. It is a LG Aristo with T-Mobile connected to a Windows 10 PC. What am I doing wrong?

Transfer Audio Files from a Windows PC:

1. Connect the LG Aristo to your computer via USB
2. Enable “Media device” / “File Transfer” at the prompt or from the “Notification” area
3. On the computer, launch the File Explorer
4. Locate the desired audio files on the PC storage
5. Copy and paste the files on the phone storage, preferably in the “Notifications” and “Ringtones” folder(s)
6. Once the transfer is done, eject the phone storage via system tray and safely disconnect the phone from the USB cord

Change the General Ringtone:

1. Launch “Settings”
2. Scroll to and tap “Sound & Notification”
3. Tap “Ringtone”
4. Select the desired ringtone and tap “OK” to confirm

Change the Ringtone of a Specific Contact:

1. Launch “Contacts”
2. Select the desired contact
3. Tap “Edit” > “Ringtone”
4. Select the desired ringtone and tap “OK”

Change Incoming Email Notification Settings:

1. Launch “Email”
2. Tap “Menu” > “Settings”
3. Select an email account and scroll to “Notification Settings”
4. Tick or clear the “Notification” check box
5. Tap “Notification sound” and select he desired notification sound
6. Tap “OK” to confirm

Change Emergency Alert Settings:

1. Launch “Messaging”
2. Tap “Menu” > “Settings”
3. Tap “More” under “General”
4. Access “emergency alerts”
5. Tick or clear the check boxes associated with “Imminent extreme alert”, “Imminent sever alert” and “AMBER alert”

NOTE: Presidential alerts are enabled by default and cannot be turned off.