Advice needed vs 71 Duster rear wheel bearing replacement

Still hanging on to my Duster (purchased in ‘71) but not driving a lot. Took it out recently and discovered that my right rear wheel bearing is noisy. I don’t recall ever servicing the differential or rear bearings. I’m assuming that I need to replace fluid and rear bearings. I’ve looked for an article or video describing how to do this - but have not found anything yet that seems to be specific to my car. Can someone please point me to an article that will help me to order the right parts and to know how to tackle the job?

My car is a ‘71 Duster that came with a 3-speed manual and 318 engine. The transmission was repaired many years ago but everything in the rear axle is original. FYI - I checked fluid in the differential and it was full. I put the rear of the car on jack stands and listened for noise while car ran in 3rd. The left rear sounds good. Right rear is making noise. The right rear wheel didn’t feel hot after I gave it a 20 mile run on the highway last week - so hopefully I’ve caught this early.