Remove Kick Starter, Plastic Cover, and outer case. Drain the oil.

Be careful when removing the outer case and you will not tear the gasket.

Item on left is Variator

Item on right is clutch

Remove 17mm nut & bell housing

The clutch will want to turn, have some one hold it or use an impact wrench. (Cheap Electric impact wrenches are available at places like Harbor Freight and Tools. They are worth their weight in gold!) Remove clutch. (Not necessary to remove large nut, clutch will come off without removing nut.)

 Remove the final drive cover

This requires removal of 6 screws, cover has locating dowel pins so you will probably have to "wiggle" cover to get it off.

Remove transmission.

These are the original gears and what you are removing.

On the left is the shaft that the clutch is on, and on the right is the main axle.

These are the replacement Athena Gears and new bearing

If you put the new shaft in the freezer overnight and the bearing in the oven on low for about an hour, you can slide the bearing on the shaft and tap down into place using a piece of pvc pipe as a bearing driver. (This assumes you do not have an hydraulic press at your disposal.)

Pay attention to the direction of the helical cut gear and install the new gear onto

Put Clutch shaft into case, install gasket, use new one if necessary, tighten up and add oil.

Re-assemble remaining pieces.