plumbingtoilet
I had good luck in the past using this product to replace a leaky flapper valve.
However, this new toilet does not have a flapper hinge on the base of the flush valve. Instead, there is a hinged piece of plastic that looks like two cylinders attached to each other at right angles. The bottom flush valve ring has a piece going straight up that this "flapper" attaches to, and I have no idea how to take it off so that I can just replace that assembly with this kit I've purchased.
It depends on the configuration of the flush valve. If it's the type with a 3-4 inch plastic tube that when lifted allows water to flush than you need to use that specific valve type from Kohler. If not and the valve is mounted through a standard (3/4 inch +/-) opening to the supply line you should be able to swap in any valve with minor adjustments to the lift handle and flapper. Post a photo of the Kohler valve.
Option #1 is always the best: use a coat hanger with a hook bent on the end.
As a second option, hemostats are pretty handy, but may not be strong enough to break plastic. But perhaps it will help you hold the ring while you cut it with an exacto-knife or some wire nippers.
If you drain the water out, then you will be able to use something like a hot knife... or just use a blow torch to easily heat a blade or a coat hanger hook. A hot blade and/or hook be may helpful for chopping the ring in two. Don't heat up the hemostats or else it will destroy the spring-quality of the steel. If you don't have a torch, a lighter will work... but try not to burn your thumb or don't let the lighter melt (pop).
Or if you are super crafty you could DIY a hot knife with a soldering iron and an exacto-blade.
Best Answer
This is what your flush valve looks like, when it's not in your toilet.
This bit should be flexible enough, to allow you to bend it out of the way on both sides.
The pins holding the actuating unit in place should slip out of the holes, and the whole piece can be removed. The best method to remove the actuating unit, is to gently pry the bracket with a screw driver on one side, then twist the actuating unit so that the pin on that side pops free. Once one pin is out, it should be easy to get the other side out.