240 differential pinion bearing

[Stetson]

I suspect my pinion bearing on the diff (where the driveshaft enters) is faulty. I get a lot of howling on the highway and at speeds from 50km/h up. Especially on light throttle. When I lift off or accelerate it kinda quiets down a bit.

Any instructions on how to replace it? Do I have to pull the whole rear end apart or can I just take the drive shaft out and work from there? Any advice is appreciated.