Help in removing sound track from one video track and attaching it to another video track in the timeline.

Right-click (control-click) on the clip and select Detach Audio from the menu that pops up.

The audio will now be separate and you can drag it anywhere you want.

To merge the detached video into the desired video track, you need to export the video and audio track to your desktop. Then the audio track will become embedded in the video. You can import the merged clip back into iMovie.

When you delete a clip from the timeline, everything that is coupled to it will also be deleted. You need to uncouple the clips. You can do that by placing your cursor on the independent audio clip and, while pressing down, drag it down to a lower audio well until you see the coupling pull off of the video clip above. Or you can slide clips down the time line to remove the coupling to that clip.

Make sure that you don't have multiple clips selected when you delete one clip, because everything that is selected will also be deleted.

-- Rich

You copy and paste them into a new project. Then export to your desk top. From there import into your original project.

— Rich