i am guessing you are talking about porting.?
it is not a lot of work if you know what your doing.
it takes about 5 hours for me to do one but you can do a mild clean up in a few hours.
if you are going to do this yourself do some reading first. the "two stroke tuners handbook" is a good start.
here are the basics you want to raise the exaust ports, lower the intake, widen both, point the intakes to the carb, smoothout the intake tit, smooth out the bottoms of the transfers, and chanfer all the ports at the cylinder wall.
i think that is eveything.
big ports on these motors are going to be about 4 to 5mm larger than stock.
a ported motor with you basic mods (pipe, water box, air cleaner, prop, and 44) will run like a totly different ski and pick up 10 to 15 mph over stock.
also if you take the motor apart put new crank seals in it cuz you will never get it to run right if it is not sealing.