I guess this is the first time you have heard of this problem. Well, I found a solution by calling several of the plumbers who work at Home Depot and piecing together the clues. Since I couldn't remove the stop, or even turn it, I found an alternate solution. Here it is:
Turn off water supply to tank and drain the water by flushing; lift the canister with one hand; reach down below the canister with the other hand and grasp the bottom of the guide using thumb and one or two fingers; turn the guide from the bottom 1/4 turn counterclockwise and lift it out with the canister; remove and replace flat seal; reinsert guide into guide hole and turn 1/4 turn clockwise with the stop to reseat; make sure flush handle chain is reattached to canister is it came loose; turn water back on and use your toilet.
We like the Kohler Cimarron because it doesn't get clogged like our old toilet.
Hope this helps someone the next time they have this same problem.