take your time, get a good set of allen sockets for the rear sprocket and a impact screw driver, (the kind you hit with a hammer) to break them loose or they will strip, also if you are handy with a propane torch it wouldn't hurt to heat them up a tad to soften the loctite from the factory. the front is no biggie remove frt sprocket cover and remove the bolts or clip holding the frt sprocket on. check the seal behind the sprocket while you have it off and make sure its not leaking everything should look nice and dry, take your time and clean up everything while you have it apart. adj chain tension and lube it after a very short ride to heat the chain up. and dont reuse the cotter pin that holds the rear axle nut from backing out, matter of fact dont ever reuse cotter pins. that would be a better habit to have! get the torque specs and torque all bolts etc to correct torque specs, if you don't have one borrow one, you don't want to strip,break or have these back out on you, also check your wheel bearings while you have it all apart, and it goes without saying but i assume you guys are also changing out the chain with the sprockets? unless your scoot has got very low miles you always want to change out them all in a set.