That looked like a good conversion in the video.
The only problem is that Blitz is out of business, and I haven't seen anyone selling a gas can with that type of spout any longer.
So unless you can find a discontinued Blitz can with that spout assembly, the video is useless for currently-sold cans...
Unrelated: I have an old 2.5 gallon can with a rounded top, vent opening, and rubber hose pour spout. The gasket inside the spout has shrunk over the years, so the spout would leak when pouring.
I found an EZ-pour spout ($10 at Tractor Supply) to be a perfect replacement. If the kit designed for "gas" (black spout) isn't sold in your state, the kit for H20 works just as well.