Either at the request of the debtor or the suggestion of the credit repair agency some companies will wage a war with the credit bureaus concerning legitimate items in the hopes that the creditor either ignores the correspondence or gives up on the paperwork required with the result that legitimate bad credit items end up removed. I personally would advise anyone considering such an endeavor that attempting to remove proper items can constitute fraud and avoid any such actions.
Some organizations claim they will issue you a new social security number or create a completely new credit profile for you. Organizations of this type fall into one or two categories, those who are scam artists and liars and those who are operating illegally. Even if an entity some how could create a new credit profile for you such an action would be completely improper under the law. I personally recommend that any organizations making claims of new social security numbers or new credit profiles be avoided.