Axle seal and bearing replacement

Hi.....Brand new to this, but have been following on and off for a few years. I am in the process of "fixing" a bunch of the things that have been bothering me for years on my "73 Dart Swinger. I am the original owner, bought it brand new when I was 18. I have since swapped out the original 318 for a 1970 340 motor many years ago and bored it out .20 over, cammed it up, headers, intake, carb and MSD. She runs like a beast, 398 HP on the dyno. The tranny and axle have also been swapped out from a '70 Duster, 727 and a 8 3/4". I seem to have a slight leak by the rear brake/axle area and am looking for a tutorial or "how to guide" on this specific axle for seal and bearing replacement, should it need it as I pull it apart. I have seen a couple of Youtube videos of "general" guidelines but nothing specific to the Chrysler 8 3/4. Most of it looks pretty simple, but having not done it before, I don't want to screw it up AND want to be able to order the correct parts......can anyone offer any direction....thanks a lot!!!!