How to fade purple scars?

I have alot of dark, very raised purple self harm scars from cuts that needed stitches (some got stitches some didnt) and deep burn scars. They have been the same for almost a year. Wont disappear at all and are extremely visible. The are all down my arms and legs. How do i fade them. I know i shouldnt have dont it in the first place, im clean and i got help.