PCX Borekit upgrade Final Drive

[patmacessex]

First of all I would like to make a small apology for not posting enough here but I find the forum quite confusing plus I get no notifications when I get replies.

Anyways
I've ordered a 170CC Malossi upgrade and would like to adjust the final drive gear ratio... to get a higher top speed
Now I've seen some proper posts here but they're quite old... and I have the 2016 model
The post was talking about having an industrial press to get parts out which put me right off.
Now I'm confused again... I can put 1000CC in the PCX but if the gear ratio and or the RPM doesn't change it will have roughly the same top speed (Yes it will be able to withstand wind etc with the more power but thats about it) SO my question is what do I need to order and what ratio and are they easy to fit and with easy I mean drain the gear oil take the gearbox apart fit the new parts and put it all back together with a new seal...?
Another thing that confuses me a little is should I buy for 150cc or for 125cc as it will be a 170 cc after upgrading so will that make any difference or is that just the way its advertised. Now most posts talk about the "Kitaco Final higher gear ratio for Honda PCX 125/150" And then getting the Yuminashi kit... which ratio should I buy from Yuminashi as they have a ton of different ratios.... And is this the way to go??? Thank so much in advance as this would be one step further in rebuilding this bike....