How can I place content on an ipad with a hand scrolling over it?

We have and already produced commercial but i need to make edits and repurpose it. Here is a link to what I'm referring to

https://www.youtube.com/watch?v=EX27VJUJQfA

0:17 second mark the woman proceeds to click a button on the ipad. How can i change the content on the ipad screen and have her hand go over top of it?

Any help will be greatly appreciated.