How hard is it to change out a rear wheel bearing on a 7 1/4 rear?

How hard is it to change out a rear wheel bearing on a 72 Dart 7 1/4 rear?

I have not got a lot of money to work with right now, I was thinking of taking one out of a parts 7 1/4 rear end that the housing is junk on that come from a 74 Scamp, would 74 bearings be same as 72?... I know I got to get new seal & gasket! What do I need to put it back in?
not sure if bearing is same but wha