replacing rear axle bearing on a bob cat 225 compact tractor

[Randy CT225]

How do you remove the rear hub on a bob cat 225 tractor

 

[LD1]

Cannot help with removal cause I'm not familiar with that model, but why did they fail? It seems pretty uncommon on modern and even old tractors to have a rear axle bearing failure. It's low speed and mostly submerged in oil. Did it run low on oil? Or never changed? Some other failure sent metal shards through the system?