how to replace rear bearing only...not hub and bearing?

So I replaced rear bearing on a 2009 aveo only a few months ago and it didn't last. They are a heat shrunk fit and didn't want to move with a 10 ton press,so I knocked the bearing guts out and then welded a bead inside the old race to get it out. The welding will shrink the race allowing it to fall out
To install, I heated the hub with a torch and froze the bearing in dry ice. Only lasted about 18 thousand miles. Why?? Maybe dry ice is not good for a bearing? or the hub was too hot and there was too much heat transfer to the bearing after it was dropped in?
Any advice? From searching on line, I seem to be the only person that has tried to replace the bearing only.

the dry ice would be fine for a race, but a sealed bearing? it would crystalize the grease, would it not? How many total miles do you have on the aveo? ie how long did the first bearing last?

I think since it is only $35-40 difference in price between the two, and the fact that not everyone on here has a 10 ton press. most people have in fact replaced the hub.

Wow, never tried to replace a back bearing. Did try to replace a front bearing, did the same, press fit the bearing back into the hub, ended up replacing the whole hub and bearing a few months later when the pressed one failed?!? Seems to be the same situation that you are in.

The thing I have found with pressing sealed bearings is typically (unless you have the right tools) you tend to put a flat spot on the surface while pressing on the bearing instead of just the race.

Imho I'd go with a cheaper brand assembly before a more expensive brand individual bearing.