How to remove acne mark.?

DEPENDS!!!: Different acne marks must be treated in different ways. See a dermatologist.

Manage ongoing acne: The red marks after acne are healing and you cannot and should not try to affect them. The brown marks are post-inflammatory pigmentation and you're more likely to disfigure yourself if you try to bleach them. The depressions are scars and can be managed by a dermatologist or plastic surgeon. Especially, manage your current disease with benzoyl peroxide plus prescription Rx if required.