the factory service manula is where I learned to rebuild them
there is a company out of the Portland area that has the brg kits available for approx $150, they come with gaskets as well
you will need 2 types of snapring pliers , pin type & an expander for flat ring type
you also need some kind of tool / wood dowel or even heater hose to hold the brgs in place inside the countershaft while you install it into the case , I bought the Miller tool to do this