Do not go under the car unless the car is support by a jack stand.
Put a block in front of one of the rear tires and another block behind the same rear tire. This prevents the car from rolling in either direction while the front is jacked up.
To operate the jack stand, turn clockwise to lift up and turn counter clockwise to low down.
Use a pry bar to remove the old brake pad from the bracket.
Use the same procedure for removing the pads on the other sides.
TIP: Using C-clamp to compress the caliper to refit the new brake pads
After removing the pads, you can check the rotor for irregular wear or damage. Run your finger across the face of the rotor to feel for grooves or chipping.