How hard is replacing the PTO Clutch on a John Deere 116 Lawn Mower?

It is a 116 John Deere Riding Lawn Mower, it runs great but whenever i try to engage the PTO the blades won't spin. On rare occasions it will spin but if i try to mow grass the blades stop turning, the repairman told me that it was most likely the PTO Clutch. So like i said how hard is it to replace?How hard is replacing the PTO Clutch on a John Deere 116 Lawn Mower?Assuming you are talking about an electric clutch. It is held onto the crankshaft with a bolt in the center of it and some bolts holding it to a bracket. Not a hard job. The worst part is the price of a new one. There is an ajustment to the clutch. There are three nuts looking at it from the bottom. Near each nut is a slot. You adjust the nut so that the gap in the slot is .012%26quot; with a feeler gauge. Are you sure that it is the clutch and not a bad belt or a missing spring on the tentioning pulley? If it is an electric clutch, they cost about $300.