How to get rid of old burn scars/hyperpigmentation? (Photo)

The picture isn't the best but my left has dark brown "scars" from cigarette lighter burns. These marks are now almost 5 years old and have never gotten any lighter. I assume I wasn't careful enough to keep them out of the sun when they were fresh. Is there anything I can do at home to help lighten them? I have tried mederma and the silicone sheets. Would a lightening cream like hydroquinine help?