How do i get rid of dark knees, and scars?

I am a black teenager and I have beautiful legs but my dark knees and childhood scars (from being silly lol) just ruin them...


I really want to start showing them off now so how do i get rid of the dark knees and dark pigmentation left on my leg from healed scars?How do i get rid of dark knees, and scars?
Rub lime juice on your knees