The only Kohler toilet i could find was the "Wellesley" it's a square tank tappering smaller at the top.
I have the parts breakdown and it does show 3 bolts coming from the tank through a triangle flange and three nuts at the bottom of the bowl, but does not show all the connections in the picture.
If you unthread the bolts from the top it should loosen the bolts but again i'm not sure where the back one connectes to.
I tried on the internet to get a picture but it doesn't show. If you want i can fax you the breakdown.