Hello

I'm very new at video editing. I desperately need some help on how to go about editing a video.

The video is a presentation and the recording has the speaker only in it. I have the power point slides and the timeline where the slides must appear. In other words, I have to make the speaker's face disappear and replace it with a slide for about 3 seconds while the audio continues.

Can anybody help me in finding out what is the easiest and simplest way about getting this done. Thanks a gazillion in advance

Thank You