Those markscould be gone in less than 2 weeks by doing a full water fast. By day 5, the body enters autophagy and begins to break down cells for energy. The body targets the damaged cells first, allowing the scar tissue to break down rapidly and new fresh skin to surface in it's place. By approximately day 7-8, your skin will begin to flake upwhere the hyperpigmentation marksare located (similar to what occurs after several weeks of accutane). Once the flakes peel off naturally, you'll have new evenly toned skin where the marks used to be.
Days 3 and 4 are the most challenging. Because you're at that point between where you haven't consumed any calories for a few days, but your body hasn't quite entered autophagy yet. On day 5 the hunger should subside as the body turns to the damaged cells for energy, allowing them to breakdown. On day 6, you'll have more energy than you know what to do with and a mental clarity that you haven't experienced since you were a child.
I know this doesn't seem possible. But readup about autophagy and ketosis. The healing powers of fasting are limitless. There's a reason why cultures have been doing this for thousands of years. Not just human's either, but other living animals do this as well in order to heal wounds and fend off deadly diseases.