It's not in your default layout.
If you've never heard of it you probably will never look for it, let alone find it.
So here it is.........

Regards
Douglas

PS. This tutorial has been updated after Siencs kindly pointed out an important point I had missed in the original Tutorial. Thank you Siencs.

Hey Douglas,

Just wanted to point out that the replace edit command is a playhead to playhead replacement. The frame that you park the playhead on in the source monitor will be inserted at the point that the playhead is in the timeline. So if you want the frame in the source monitor to be the inpoint you need to position the timeline playhead at the first frame of the clip to be replaced.

Thanks Siencs,

A very important point.
One that I missed completely.
I will redo the Tutorial and make the necessary adjustments.
It may take a day or so before I get round to it.

Thanks,
Douglas