Where can i fine manual for engine replacement

TO REMOVE THE PULLEY FROM THE CRANKSHAFT END:

Remove the blade belt and, if needed, the deck to give yourself more room to work. Apply your brake pedal and lock it down, this will relieve the tension on the ground drive belt.
If you have an electric blade clutch, find the plug where the wire goes over from the clutch to the frame and unplug it.(Electric clutch will be heavy when unbolted so be ready for it.)
In the center of the pulley or blade clutch you will find a long bolt (most likely a 5/8 head on it) You may need a deep socket to reach it depending upon the type of stack pulley on it, remove this bolt and the pulley should slide freely on the crankshaft. slide it downward and slip off the belt on the top of the pulley then remove the pulley the rest of the way

The Kohler website has engine manuals. You have to have your serial number ready. I found and downloaded the manual for my 1998 20 hp Kohler Command there.