I didn't bother looking up the model numbers to see if this is a vertical shaft engine or, as has been suggested, a horizontal shaft engine. On my 2005 Khohler V-Twin (I forget the model, but it's something like 24 hp on a Cub Cadet lawn tractor with a 54" belly mower) I seem to remember a bolt near the bottom of the engine, possibly where the oil dipstick tube mounts? Or possibly near the starter motor?
Also, as was mentioned, the SCREEN bolts (up on top of the engine, over the flywheel) may also have to be removed.
As I get older, I can say that wearing a headlight (literally) and reading glasses are becoming requirements in situations like this. Between being able to clearly SEE, and carefully feeling what IS loose and what is not, you should have this knocked.
Also, FINDING A YOUTUBE video of this annual maintenance procedure, for your exact model, should not be difficult--or even a different model with the same engine.