I need someone to teach me how to swap faces in a video with motion tracking

I need to be able to swap faces on a video. The faces I will be adding in need to also be videos. I know how to add in an image with motion tracking but need to be able to do this with a video so that e new faces move.

I have attached a link below with an example of what I need to be able to do. I have Adobe After Effects and Apple iMovie so ideally one of these would be best.

EXAMPLE: https://www.facebook.com/www.JOE.co.uk/videos/570111193152951/