Hello,
The treatment for such hyperpigmentation includes various skin creams like hydroquinone, azelaic acid, corticosteroids,
tretinoin cream and laser treatment.Apply
hydroquinone cream on this scar and it should go away in a few days to months.If it still persists then you can go in for laser treatment, Chemical peeling or microdermabrasion. Avoid picking, harsh scrubbing, and abrasive treatments unless prescribed by a dermatologist during this period.
Hope it helps.