Radiator service, the basics
If you still are not sure that brake repair is necessary, you can eyeball the pads through the brake housing view port before removing the wheel. Once you determine that brake repair is necessary, then remove the wheel and the lower bolt on the brake housing and swing the unit up and away from the wheel. Now you can begin the actual brake repair. You should be able to see the old brake pads clearly once the housing is out of the way. Sitting loosely on the side of the disk without anything to hold them in place, they are easily removed.