Changing the propeller pitch

I agree with Rotax Wizard. It depends on your aircraft mfg. POH / Maint. manual. Plus is it a certified, SLSA or Experimental aircraft.

In general terms if you have an experimental LSA the owner could adjust the prop. If it is SLSA then an LSRM or A&P could do it. This said whomever does it should have a good understanding of what they are doing, why they are doing it and why Rotax wants certain rpm spec. This said in some of the early LSA days some Mfg's set the max rpm to 5200 WOT in level flight. So their understanding of prop performance and engine stress was bad. This was an issue with top LSA Mfg's. My big prop research project years ago helped prove and disprove several Mfg's ideas about props and their designs.

Adjusting prop pitch is easy. Once you have a good understanding of the physics involved you can even determine the approximate amount of adjustment you need to accomplish your goal.