Changing your social security number?

I know I've been MIA for awhile, but hope everyone is doing well. I thought I might come to you guys with a question.
So, when I was 18 I was informed from a credit union when they were looking up my ss# that another woman's name is using my number. At that time I filed a police report and informed the credit bureaus, but nothing came out of it. ( btw this lady has been using my social security number since I was 7 years old)
Recently my mom met an attorney and asked him about my issue, and he had someone look deeper into it. Turns out I have over 25 people using it and they are all in the state of CA. He told me there must be a social security " mill" selling my number topeople and it would be difficult to get them to stop, SO he suggested I change my number all together.
I have recently gotten a car loan which was difficult in itself because of this fraud issue ( however my credit score is still good) and would like to solve this before my wedding next year, and before I purchase a home, etc.
I dont know how to go about doing this, surprisingly I found very little information on the internet about changing your number. Hoping someone here might have some helpful information for me :)

This would not be common, and I'm sure this is why there is nothing online about it.

You will need to call or go in to the Social Security Administration office for your area. If you call, prepare to be on hold for some time before getting through to a person. Then explain that you have proof of 25 people using your number, and why you want to get a new number. They should be able to help you.

I wonder if this lawyer could refer you to the correct person, or even do it himself for a reasonable fee.

ETA: What's interesting to me is that here in Canada we don't get our SIN (Social Insurance Number) until we are 16 years of age.

Hope you get your new number soon!