Kohler Cimmaron Toilet Tank-to-Bowl Flush Valve leak Calamity - How to Fix DIY

I could find no information about this kind of leak on the Cimmaron, so I'm posting this to share our experience in getting this fixed. I have to say these high volume flush units have performed flawlessly for the 8 years since I installed them. That means NO CLOGS. It's a great product in our opinion. Timestamps: 0:00 Overall performance review 2:18 The problem 2:40 Removing the tank 3:34 Removing a stuck nut 4:22 Why did it leak?? 5:22 Parts list / where to buy replacement parts 7:31 Installing the replacement parts 9:18 Bonus content!