What is the best way to replace the flapper on a Kohler one-piece toilet?

To replace the flapper on a Kohler one-piece toilet, first turn off the water supply to the toilet. Remove the tank lid and flush the toilet to empty the tank. Disconnect the flapper chain from the flush handle and remove the old flapper. Install the new flapper by attaching it to the mounting ears on the flush valve. Reconnect the chain to the flush handle and turn the water supply back on. Test the flush to ensure the new flapper is working properly.