Retrofitting pushbutton for ignition Octavia

Hello guys, 

has anyone retrofitted pushbutton for ignition to their car which originally had a key?

TBH I just wonder if it is possible. This idea popped in my mind after by accident seeing Skoda Rapid review and in the video guy shows that keyfob has an actual key in it but car starts with button. 
 

Here is the video, you can check it from 9:10. He shows that Keyfob has a key but there is also a button.

If someone has ever done it can you please let me know how hard is it? Or some youtube videos or blog posts related to this topic would be good too.

thanks in advance