I found this and it says u can't unless you are a minister or hold certain jobs.
Article: Withdrawing from Social Security
Can I withdraw from Social Security?
The demise of Social Security in recent years has prompted many Americans to wonder whether they can withdraw from Social Security and set up their own retirement account in place of Social Security. Unfortunately, Americans do not have the option to withdraw from the Social Security system. The only exceptions to this would be those employed in a certain type of government job or ordained or licensed ministers. Even then, the only reason to opt out of the system would be a conscientious objection to government welfare. We do not recommend withdrawal for government workers or ministers because most people are not disciplined enough to put any money aside as an alternative, especially if they live on a low income.