I want to remove part of the sound in my video clip. I cannot find a way to do that. Not sure if it is possible in iMovie?
Sure you can. Select the clip then do a right-click (or look in the Edit menu) and choose Detach Audio. A purple sound clip appears below the video. You can grab the ends to crop it. Select the clip again to do another Detach Audio, so you can have to sound before and after the part you want to remove.
I am using the iMovie'09 and translating from the French version, so the wording can be somewhat different.