i have an old scar on my leg. i got burnt from the pipe of the motorcycle. i really want it removed

its been a year already. its dark brown. and its a bit big. please tell me an effective way to at least lighten the scar ! please ! (except surgery or laser)
i heard some ways like
cocoa butter (what is this? i have no idea about it. where can we buy it?)
salt + olive oil
vitamin E
toothpaste
please give me the best answer. thanks alot
