This wikiHow teaches you how to edit the soundtrack in an iMovie project to change the point where the audio begins and ends in a video clip using an iPhone or iPad.
Steps

Step 1. Open iMovie on the iPhone or iPad
The iMovie icon is a white star and a purple video camera.

Step 2. Click the Projects tab
This tab will show all the saved movie projects.

Step 3. Press the movie project you want to edit
Find the project you want to edit in the Projects list and open it.
- Alternatively, you can press the option Create project in the upper left to start a new project.

Step 4. Press the Edit button
You will find this button below the project name in the video. This action will open the movie project in the editor.

Step 5. Click on the video cropping tool timeline at the bottom
You'll see a video timeline of the entire movie in the lower half of the screen.
Pressing this option will select the entire video clip and outline it with a yellow border

Step 6. Click Split Audio at the bottom
You can find this option between Divide and Double on the toolbar at the bottom of the screen. This action will separate the audio track from the video clip.
- You will see the audio track as a blue or green bar below the video clip in the cropping tool.
- If you don't have an audio track, you can press the icon " +"at the top right and select an audio file to use as a soundtrack.

Step 7. Press the audio track below the video track
This action will select the audio track and cause a yellow outline to appear around it.

Step 8. Click and drag the beginning of the audio track
You can drag and move it to the precise point where you want the audio to start.
The yellow bar at the far left of the audio track marks the start of the audio

Step 9. Swipe left on the audio track
Swipe left until the yellow bar is at the end of the audio track.

Step 10. Click and drag the end of the audio track
You can drag the yellow bar at the end and move it to the exact point where you want the audio to end.

Step 11. Click OK in the upper left
This button is in the upper left corner of the screen. It will save the edits you have made to the movie project.