HF200 comes with PWK and easy to tune, like anything easy when you know how.. All PWK carb have a breather so will leak if you do not drain it. Saying that my 250 never leaks. PWK is a much better carb than the Walbro for tuning.
I think it's a very easy job. it's just a new head, cowl, carb etc.. not rocket science.. But if your a monkey with tools then it might be worth getting someone to do it for you..