I believe the BBB (full version) explains the procedures on the rear end quiet well. All the parts you need are still available. If money is no issue, MB will be the best source. Otherwise, the German vendors (SLS, Niemoeller...) tend to be less expensive than the local ones (Buds, Authentic classics...) assuming you buy enough parts to offset the shipping cost.
Sometimes parts are still available from known discount retailers such as Pelican, Autohaus, Rock Auto......
There is also a lot written on the forum here on rear ends...
I think you need to be more specific with your question.