Apple Final Cut Express HD - Manual (Page 345)

Chapter 25 Three-Point Editing 345
VI
5 Do one of the following:
 Drag the clip from the Viewer to the Replace section of the Edit Overlay in the Canvas.
 Press F11.
The selected area in the sequence is replaced by the source clip. Final Cut Express HD
automatically calculates the clip duration.
Before a replace edit
After a replace edit
New clip replaces the
selected area of the
sequence.