Two extra observations/steps that should help everyone out.
I have just fitted a 14 tooth sprocket (30mins ago) and everything was simple except for one important step that the above instructions (and Ducati's service manual) don't mention.
You must remove the clutch slave cylinder before you can remove the sprocket.
Undo the three screws (15) securing the clutch slave cylinder (14) to the engine and withdraw the unit from the crankcase.
This will let you slide the sprocket off when the time comes.
My other observation is one of SAFETY. Be aware that if you are working on your bike with the side stand down, when you remove the 3 bolts that hold on the left footrest the bike can fall over!!
This is because one of the bolts that holds the left footrest holds the side stand.
Either use a paddock stand
Have someone hold the bike up while you remove the footrest then replace the bolt that secures the side stand and continue to work on your bike. Just remember to do the reverse when you start to reassemble the bike.
I hope this helps everyone.