Breaking and Creating Links
You can break or create links in the timeline, but the links of the master clips and their associated files on the drive remain unaffected.
To break a link:
In the timeline, select the video portion of a linked clip. Both video and audio tracks of the linked clip are selected.
Choose Clip > Unlink Audio and Video (Figure 7.61).
Figure 7.61. Choose Clip > Unlink Audio and Video.