Growling or grinding from the rear wheel that increases or decreases with the speed of the car is almost certainly the wheel bearing. All cars have wheel bearings. While it is a fairly simple operation, you need a special tool that you can sometimes borrow from your local auto parts store when you buy the new bearings. You will need a bearing race driver tool to press the new bearing in. You should replace both bearings on the rear axle at the same time. Here is the procedure:
1. Remove your disc brake calipers and caliper bridge to remove the rotor.
2. Remove the bearing cap. This is a press fit and to remove it grab it with your channelocks and work it back and forth until it pops off. Be careful not to crush it.
3. Once the cap is off you will see a cotter pin, remove the cotter pin and remove the retainer ring. If your vehicle has a castellated nut, you will not have a retaining ring.
4. Using your channelocks or adjustable wrench, remove the nut from the spindle.
5. Next remove the outer wheel bearing and washer.
6. Slide the rotor or drum off the spindle.
7. Remove the grease seal and take out the inner wheel bearing.
8. Wipe all the old grease from inside the hub.
9. Remove the bearing races from the hub.
10. Take a punch with a flat narrow tip and place it on the back of the race.
11. Tap the race out, alternating from side to side so it comes out evenly and doesn't get cocked in the hub.
12. Once it's out, flip the rotor or drum over and do the same for the other race.
13. Clean the inside of the hub with some rags.
14. Make sure the spindle is clean as well.
15. Reverse the process to install the new bearing and make sure to regrease.
That's all there is to it.