First, you need to decide whether to shorten or delete the copied music part. After finding these, find the closest sound on both sides of the required music part. Use the razor tool to cut on each beat, and then delete or copy the generated middle part. When you are finished, make sure that any gaps between music clips are filled.

From now on, your own music clips may still be audible and distracting. At this point, you can move one of the music clips to a separate layer and overlap the two layers on both sides of the cut. In this way, you can see the audio waveform and intuitively check whether the clip is closed in time. Use the outermost audio clip and use it to shorten the time you want to shorten.