1. Go to google.com
2. Type in Filmora in the search field
3. Click on download
4. Install Filmora
5. Open Filmora
6. Open new project
7. Name your project
8. Use the plus (+) import media icon to add in the video file that you want to edit
9. Click on the plus sign to add the video to the time line
10. Go to the mute button your video
11. Click on export to save your muted video file
12. Select the option that you want to export to
13. One the export is completed you will see your final muted video

To view the full video on how to mute the sound from a video with Filmora 12.5 click here