pretty simple.
Take the power wire off of the starter.. I believe it's a 12mm. Make sure and take the key out of the machine so you don't try and start it.
8mm socket.. long extension. Take the 2 bolts out of the case. Remember what size goes where. Take and pull on the starter.. it's got an o-ring packing on it so it fits some what tight to the housing to seal oil from getting out. Wiggle it and pull and it should come right out.
Thats it man. You can take it in to get rebuilt or get a new on off of ebay, which is basically the same thing.
hope this helps.