Not directly familar with '69 Cad, but being a GM of that vintage it probably has a sheet metal cover on the back of the axle housing held on with 10 or 12 bolts. If it has a "solid" axle housing (no cover on the back) and a drop out "pumpkin" you won't have to pull that, the axle will come out by just unbolting the bearing retainer (well, you'll probably need a slide hammer or something similar because the bearing is probably very used to it's home and will need to be persuaded).

If the housing does have the back cover then yes, you'll have to take that off to remove the "C" clip retainer, then unbolt the bearing retainer at the brake end. There is likely a seal down in the housing that is your culprit so don't forget to pull that out and press in a new one.

Pressed on, sealed axle bearings are the norm unless you're working on something REALLY old.