I use the 5 & 6 mm as it's definitely the easiest way!
With the 2v engines it's only one cam so really easy to do it by yourself without really needing any kind of cam alignment/holder tool.
Just don't forget to check the condition of the bearings on the rollers once you've taken the belts off as it's often overlooked by home mechanics.
There is a Haynes manual, it covers the older (carb) SS as well as the newer FI ones.
I have one and it is really handy.
https://haynes.com/en-gb/ducati/900-...wins/1991-2002