Rear axle flange removal?

[71CHEVYSHORTBED402]

Novice here, doing a ground up on a 71 C-10 2WD, 402/400 with rear leaf springs. I prefer not cut corners unless it's prudent to do so. For what it's worth, the truck has 140K miles, and has lived most of its life in the garage under dry conditions. It's likely the axle has never been touched, less fluids in the differential.

I'm not sure I should even go here, but it would nice to pull the axle plate to finish it. For that matter, to finish the axle flange as a unit as well. That said, if it's not worth the hassle, perhaps I should work with this stuff assembled.

Anyway, I'm hoping to get some idea what I'm looking at and what's involved. This image should help explain the parts I'm referring to. Thank you.