Get a washcloth warm and damp, and very gently clean the child's ears. Unless the earwax is causing the infant pain, a doctor probably isn't necessary.
Twist a corner of a warm washcloth and gently dab the ear wax from the ear. The warm water will soften up the ear wax. Do not let any water enter the ear.
Ears are very sensitive in general, but the ears of infants are especially sensitive. Because of this, it might be best to gently use cotton balls versus using Q-tips, which could poke at the ear drum.