Oh dear,
http://www.ducati-john.co.uk/alterna...aining-nut.htm Difficult to say what you can and can't do yourself without knowing how handy you are with the spanners etc.
A look at a workshop or Haynes manual might help you decide. Never seen the haynes manual for the 748/996 so don't know at what point they go for the "refer to dealer" advice
Not a cheap fix, maybe do some of the donkey work yourself and get someone who knows what they are doing to do the tricky stuff.
Ray