You should review your credit reports from all three major credit bureaus (Experian, Equifax, and TransUnion) and identify the specific errors. For each error, gather any documentation you have that supports the correct information. Then, send a formal dispute letter in writing (certified mail is recommended) to each credit bureau that is reporting the error. Clearly identify the inaccurate information and explain why it is wrong, providing copies of your supporting documents (never originals).