I will make the assumption that you don't have your report in front of you.
You can pull the report from any of the three bureaus at annualcreditreport.com for free. Once you do that, you can do what jsucool proposed. You can also write to any of the bureaus at their addresses, found easily on their websites. And I believe there are phone numbers, but I'm not sure that disputing items is available on the phone numbers.
Hope that helps.
As a general overview, the FCRA provides two difference processes for disputing inaccuracies in your credit report.
The first process is to dispute via a CRA, and let them handle it. Disputes via a CRA can relate to any information in a consumer's credit file, including credit inquiries and public record information, which are not disputable under the second process.
The CRA will refer a copy of the dispute to the party who reported the information, and solicit their recommendation, which could be a verification that they consider it accurate, a correction, a deletion of the disputed information, or no response.
The CRA then, under what the FCRA refers to as their "reinvestigation" of the dispute, considers all information, including any response by the furnisher, renders the final decision, and sends it to the consumer.
A sore spot in the CRA dispute process is that the CRAs use an electronic process for referring your dispute to the furnisher, under which they almost never include all of your supporting documentation. So the furnisher, in resonding back to the CRA, might not have the full documentation of your reasons for the dispute.
As an alternate to the CRA dispute process, a direct dispute process is available. Under that process, the consumer sends their dispute directly to the furnisher of the disputed information, thus assuring that they receive all documentation. The CRA is not part of the final determination, which is convey directly back to the consumer.
It is thus, in my opinion, the preferred dispute process. However, direct disputes cannot be used if the information relates to credit inquiries, public records information, or disputes over consumer personal identification information.
Deletion is only compelled if the dispute information either cannot be corrected to make it accurate, or cannot be verifified as accurate as reported.
In verifying, the furnisher is not required to "prove" the accuracy, only attest to its accuracy. So if they either verify or correct, deleltion is not a required outcome.
If they verify and you disagree, resolution of that issue is beyond the score of the FCRA dispute processes.
Requiring a hearing of the facts and positions by both parties is then the job of the courts, which requires the consumer to file a civil action.