To replace the narration over a section of your recording you first seek to where you want to start replacing the narration Then you would click the "Tools" menu button above the timeline and then "Narrate". Or you can just press the "N" key to start the tool. Select the section by dragging the purple bar along the timeline or if you click on the start or end of the span then you can use the arrow keys to fine tune your selection. You can also click around the timeline then use the "S" key to jump the start to that point or the "E" key to jump the end to your current seek point. If you want to Preview what it will sound like then you can press the Preview button which will seek right before the section then play through replacing the audio with silence and stopping shortly after the section. Once you are positioned in the right spot you can click the Start button or press Enter and you'll see a screen like this which has controls so you can record new narration while playing back your video. First you can choose the microphone to use and also if you'd like to record the webcam while narrating. While recording your narration you can also freeze the video by clicking on it and draw by clicking and draging the mouse. To choose the color and size of the drawing tool you can press the "Draw Preferences..." button. In addition to freezing by clicking on the video, You can also add hold points to the timeline so the video will freeze at that spot so you can talk as much as you want then unfreeze the video. For example if we wanted to add a hold point here then we'd seek to that spot and click the "+ Hold" button above the timeline which will add a dot on the timeline to show when the hold will happen. You can remove the dot by clicking the "- Hold" button again while seeked at that spot. You'll notice that there is a hold dot automatically added at the end of the timeline. This means that the tool will hold at the very end of your selection to let you finish up talking. Lets show an example by seeking back to the start and clicking the Record button. The video starts playing and we can narrate along. When the video reaches the hold point it will freeze and we can draw on the screen. When we're done with the hold we can click the "STOP Holding" button down in the lower left corner or press the H key. And when the recording reaches the end of the video it will hold then we can release again by pressing the "STOP Holding" buttton or the H key. If you mess up in your narration and you want to start over then you can click the trash can icon to restart which will delete the audio recorded, but leave any hold markers you added on the timeline. When you're done narrating you click the Done button. Anytime you make a change to the recording it is automatically saved on your computer. After the narration is done a colored span will show on the timeline where it was added. If you want to later undo the narration you can seek back to that spot on the timeline then click this icon which will bring up a menu with another icon you can press to remove the narration you added. You can also use the undo or edit history drop down to go back in time before you added the edit if you'd like to remove it. The last used tool will be listed next to the Tools button above the timeline so you can easily use the same tool again by clicking on it here.