Dark Brown Scars on Knees

I have dark brown scars on both my knees from falling on gravel. Doctor at the time said they are like third degree burn and treated. They have healed but I'm left with brown dark scars, they are not raised. I am of olive complexion. Im considering using glycolic 50% chemical peel on them. Any suggestions of advice on how to lighten these scars will be appreciated. I cal upload pictures if needed.

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