Good video.
I did not remove the skin off of my original dash. I used a utility knife and cut off the edges that were curling up and glued my cover to the remaining skin.
The kit comes with 1 tube of clear 500° RTV, some YT videos say it’s barely enough so I bought some additional RTV and used it generously around the outer perimeter and the vent openings.
Videos will also warn you against spreading RTV throughout the middle / big flat areas as this can cause waves. It’s better to glue the edges and let the middle areas “float”, there’s snowing structural reason to glue any more than the edges because you just want it to stay in place.