Second engine rebuild video. Shows how to change the oil seal and place the drive sprocket in the motorcycle. Buy the oil seals in a kit (I believe there are seven). That will make life a lot easier on yourself.
You can buy the oil seal kit here:
There are other vendors in the Online Resources post that will have them as well. You’ll find all the torque specs also in Online Resources. Remember, to remove the inside transmission bearing, you’ll need a puller and a slide hammer. These can be rented from autozone or most other auto stores.