Just checked my manuals, and they were not workshop manuals - only chassis and engine spare parts manuals and owner's manual. Nothing about piston change or other more detailed engine work in the latter.
Except from that: I have in vain sent an email to Daniela Leidl at KTM about Akrapovic silencers. Not even the faintest reply yet since that mail was sent 28th of November last year.
Maybe she was out of office or don't work there any more.
2010 BMW F800GS
2008 KTM 690 RFR
1994 Honda ST1100