Hello,
To treat acne scars,you can go in for any of the 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.
I hope that helps.Take care and pls do keep me posted on how you are doing or if you have any additional doubts.Kind regards.