[72k5]

Most of what goes wrong with hubs is the result of thickened grease and various crud. 95% of the time a good cleaning and coating of motor oil will cure what ails them. I would think that parts for the stock hubs would be pretty available. There were a gazillion of them produced. The 4x4 shop I worked at had a big box full of just stock hub parts. A shop that does a lot of 4x4 work may be a good source of parts should you need something.

The stock hubs are easy to work on, but an exploded view would probably be helpful if you've never seen one before. Any manual should have a breakdown. If you don't want to buy one, the local library almost certainly has something that will give you what you need.

BTW, if the hubs have been unserviced long enough to gum up, the wheel and spindle bearings are probably due for a repack as well. It would make sense to do it all at the same time. For that you'll need a special socket and a torque wrench. It is also easy, but you should have a book to guide you if you've never done it.