dont know much about these bikes, but compared to other 2 strokes, the throttle cable will be a breeze to replace. Now the gears will be harder but not horrible... Remove he clutch cover, and the gears. Not sure but may have to pull the clutch plates and clutch basket to get the gear off. Most bikes require this.
Pretty sure you gotta take the whole damn thing apart and split the cases to replace gears. Not saying it isnt worth it. It prolly is.
However, it depends. If you do it yourself and know how, yes its worth it. If you dont, consider how much its going to cost you to pay someone to do it.
And if Im wrong about splitting the cases, I apologize in advance, but Im pretty sure thats standard stuff on these things.