Use an audio processing software, such as Au, open Au and play a movie at the same time. Record the la la la la you want through Au computer recording, and transfer it to music software such as QQ Music or Kugou. After passing the review, you can download it and make it your text message ringtone. Of course, there is another way, that is to record it and set it as a text message ringtone, but the sound quality is not good.