Separate the tractor PTO from the end PTO connector on the King Kutter. Do this by pulling out the locking pin with pliers and pulling the two PTOs apart.
Pull the tractor away from the King Kutter deck so you have room to work.
Use a pipe wrench to remove the end cap of the PTO shaft casing on the PTO end that attaches to the pulling tractor.
Use a socket set to remove the retaining bolts holding the PTO end in place under the cutting deck, where it engages the blade clutch.
Slide the old PTO shaft from the shaft casing and slip the new one in. Tighten the retaining bolts holding the end of the PTO connected to the blade clutch.
Replace the end cap on the PTO tow-connection end with the pipe wrench.
Back the tractor up and connect it's PTO link to the King Kutter's PTO link and slip the locking pin in place.