If you are having trouble with your Kohler One Piece Toilet, then you may want to either repair it yourself or hire a local plumber. It will all depend on what is broken on your toilet and how handy you are with plumbing hand tools.
One of the most common problems with Kohler One Piece Toilets is that they clog easily if you use lots and lots of toilet paper. In fact in some cases a good meal at a fast food joint could make you wind up in the bathroom all night, using rolls and rolls of toilet paper to only clog the toilet.
So if you happen to clog the toilet you can either use a toilet auger or small snake to unclog the toilet. If after doing so you cannot repair the toilet yourself you should think about calling a local plumber or you could also try to troubleshoot the toilet yourself.