I was just driving back to MI from GA this past Monday and I heard a moderately loud "whirling" sound coming from my back right tire (I think). It definitely sounds rotational, as the frequency increases with speed. Could the bearing be bad? And if so, how much hassle would that be to swap out?

Any help wold be great.

Thanks

'00 4cyl 5spd Coupe w/ 65K miles