These get written as though they were the same letter. They are not, and being clear about which one you are making is what gets a useful answer.
1. Correcting inaccurate identifying information. The report says something factually wrong about who you are. You are asking for a correction to the accurate detail, and you may need to show identity documents to support it. This is the ordinary case.
2. Removing obsolete information. An old address or a former employer is accurate history, not an error. You are not saying the bureau got it wrong; you are asking that information you no longer want carried in your file be removed. Bureaus commonly honour reasonable requests of this kind, but a former address is not inaccurate, so this is a request rather than a dispute about accuracy.
3. Identity theft. If someone used your identity, the identifiers on your file may have been changed by the person who did it — a different address so that mail goes elsewhere, a different phone number, sometimes a different employer. Do not treat that as a clerical correction.
4. A mixed credit file. Another person’s information has been merged into yours, usually because you share a name, a similar Social Security number, or a family address. The identifiers are the symptom; the accounts are the problem.
If identity theft is involved, start there instead
File at IdentityTheft.gov first and work from the Identity Theft Credit Report Letter Template. Section 605B of the Fair Credit Reporting Act, 15 U.S.C. § 1681c-2, gives you a block on information that resulted from the theft — a stronger and faster remedy than an ordinary correction request. An address the thief added is part of that picture, and it belongs in that process rather than in a standalone correction letter.