Two years ago i used credit repair service from Credit Attorney. It was worth the money I paid as most negative statements had been removed successfully.
It worked as follows:
1. I forwarded my credit reports from Equifax, TransUnion and Experian to the Firm.
2. After several business days i was informed about negative statements which had been found in my reports with the advice and options to fix.
3. During the time company worked on my case i received several letters from credit companies which i forwarded to the Firm.
It took about 2 month between the day the Firm start disputing and i received an updated report.

Beware of companies that promise to help you re-establish your credit for a fee. Their ability to change the information that appears in your credit file is no different than anyone else! Only your creditors are able to alter this information. Therefore you do not need to pay a third party to obtain, discuss, review or make changes to your credit report. You have the right to access your information and make changes to your file if there is an inaccuracy or if you want to include a comment.