The only successful reduction/near removal of Keloid scars I have had is by sets of cortisone injections. I've had great results. Have a plastic surgeon, not a dermatologist, do them. My plastic surgeon told me to never scrape or cut them off -- they will only return worse than before.
Hope this helps.
I don't know much about keloids, but I do know that once you remove scaring it will grow back and sometimes even worse then before. I would make that decission with your doctor.