You could buy this as a gift...
Don't watch the making of a KB by Pavel. Damn annoying, lol. At least DD has a modern website now.
Maybe check out to see if a local CF affiliate or similar gym is gonna have a KB intro session. Some do from time to time. You can start off by showing your dad what you do with your KB.
One of those variable KB that only go up to about 30 or 40lbs might be better here than just showing him your 20kg or getting even a 16kg. I find it kind of silly to buy something smaller than 11kg which is why I say the adjustable ones. However, I'm not a real fan of how they handle.
DD also has a DVD for seniors but honestly I don't think I would buy something like that for my grandparent or dad. Especially since it has a senior female on it. Yeah, that's how it is. Oh well.