There is a lot of information what to do (i.e. page 53), and for the easy things how to do/check.
With this and a general purpose scooter mechanic book, one should manage to do <=95% (depending on available tools).
I know only of 2 books in german special for Kymco scooters, from Stefan Zipperer and Christoph Schneider.
But they are more general for many Kymco scooters and won't substitute special Kymco training (AFI injection module, Xciting Variator, ...).