Ball Bearings

Seems like the bearings on my mothers car are in need of a change, really don't know much more about the situation than that. The only real experience I've had with bearings myself is when they went on my skateboard when I was a kid, I was rolling down a hill at the time, the result wasn't pretty. I quickly ditched my skateboard for roller blades, probably not the best alternative, but luckily the bearings held out beyond when I got bored of them.