Cadillac CTS 2003 wheel bearing noise

Hi all;
I just got a 2003 Cadillac CTS with 110,000 miles. Seems like a nice
car But:
I hear a rumble when going low and medium speed, sounds a lot like
wheel bearings.I haven't yet rotated the tires to see if it is tire
hum, likely not because noise is a some lower speeds as well. I know
the CTS is rear drive independent suspension so my question is:

How difficult is it to change the rear bearings? My guess is that it
should be a sealed hub assembly. Just unbolt the axle (halfshaft) nut,
unbolt the assembly from the upright, and voila, reverse procedure to
install.

Are there any tricks to this repair. Any strange procedures for the
ABS sensors?

Thanks in advance
Gary / Atlanta