If you have to replace bushing/bearings, then you are going to have to tear the unit down to bare bones as the bushings are difficult to get out otherwise.
First you must remove the spindle assembly. Just unscrew that as you would a large nut. Then you can pull the gypsy
off the shaft. If it is seized, you'll need. To use a wheel
puller, but it will come off. That will expose the clutch
cone. In order to get that off you need to drive out the spring pin. A pin driver works best, but any flat head
punch that is sized just under the diameter of the pin will work. I can't remember the size off the top of my head
, but I think it is around 1/4" or less. The clutch
cone should come off pretty easy, but if not, use a puller. This is made of tuffnol and is somewhat fragile so ease it off. This will expose your shaft completely and allow you to remove the cover. On the port side of the unit you will have to pull the drum off. Again, a puller works great here. Once inside the unit you can remove the chains by removing the master links at the operating lever. You only need to take off one end of the chain to accomplish what you want. This will free the gears and you can now pull the shaft with the gears from the housing. At this point you can go through the whole unit and decide what needs replacing and repairing. Let me know if you get stuck somewhere. Good luck.