How To Remove Keloid After 2nd Degree Burn?

i received 1st and 2nd degree burnt with chemical. i did skin grafting surger to my face, entire right arm neck and chest.after the surgery i had some terrible keloids. what can i do to get rid of the keloid its in all the plces i received burns and how can i strecth the skin graft on my face under my face, its making my face look lean.