Which treatment should I do for damaged skin due to steroid injection? (Photos)

Dear celoosa95,
it is hard to tell for sure without an examination, but you will most likely need scar revision in order to get better results. If you are considering a surgery, I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD

It is doubtful that laser will be of much benefit, but you could have the scar excised and then use scar products to help minimize the hypertrophic scarring.

I'm sorry about the trouble you're having with her breasts.  Hypertrophic scarring frequently does benefit from steroid injections.  Unfortunately thinning of the skin and fat atrophy are potential complications of steroid injections.Itis unlikely that this issue you are having will get solved with a nonsurgical option.I think your best option will be to have this excised.  Unfortunately, this will again put you at the risk for hypertrophic scarring.I would suggest speaking with a board certified plastic surgeon about the options.