How to add a MP3 ringtone to an Android Phone
1) Connect your Android Phone with your Computer,
2) By using an USB cable. After connecting your Phone with the computer a dialog field
will open on your phone and confirm that your phone is connected.
3) Click on Start - Computer
You will see all all Hard Disk and a field whith shows your Smartphone Folder.
If you do not have a ringtone folder, create one.
4) Copy paste your MP3 ringtone into the ringtone folder of your Smart Phone.
5) On your smartphone you can now choose your new ringtone. Go to settings and sounds.