Go online and pull a Kohler engine manual for the specific engine in your tractor. Most of the K-series Kohlers involve loosening the governor arm, taking needle nose pliers to turn the governor shaft the appropriate amount, then re-tightening the governor arm in the correct position. I've done it a few times and it's more of a feel as you go kind of operation, but the manual tells you the right way to do it.
The Kohler manuals are free to download from Kohler. You just need the engine model number and serial number if you can read it. It's on the stamped plate on the flywheel housing.
