As above… cases are split to do the gearbox bearings and replace the o-rings in the gearbox crank seal side (all good, just worn o-rings appear to be the source of burning gear oil). Anything particular to watch out for when reassembling?

Never done it but between the KTM manuals and the Jim Snell videos, should be able to figure it out. Any pointers welcome. 

Main bearing wise make sure LHS bearing hole is aligned with appropriate hole in case when reassembling, (2003 - 2018 bikes) and gear box just take it apart, and put back together with the gear set in Neutral, and it's easy.

You'll need a flywheel puller, and a primary drive gear puller (RHS of crank). That's it as far as "special tools".