To change the music of Douyin videos, for published works, you can follow the following steps:

1. In Douyin APP, enter the "Me" interface, and Find the video you want to change the music to in "My Works" and open the video page.

2. Click the three dots in the lower right corner of the page and select the "Download to local" option. After that, select "Save to Album" and make sure the video is saved in video format.

3. After the download is completed, return to the Douyin homepage and click the " " sign below to enter the shooting interface.

4. In the shooting interface, select the "Album" option, find the video you just saved, and confirm the import.

5. After importing the video, click the small arrow on the right side of the page to proceed to the next step.

6. Click the small horizontal line icon at the top of the page, adjust the original sound to 0, and confirm the adjustment.

7. Click "Add Soundtrack", select the music you want to change, and click Use.

8. After adding music, click "Next", edit relevant information, and finally click "Publish". The above steps can help you change the music of an already published Douyin video.