The key to repairing bad credit is to write a properly formatted letter of dispute to one or all of the credit bureaus and send them out via registered mail. Here's a step-by-step guide to writing a letter of dispute to get rid of those black marks off your credit report for good. Remember, it's your right to file a dispute.
The Fair Credit Reporting Act makes it very clear that anyone with unauthorized charges or incorrect information in their credit reports can dispute them. This video tutorial shows you how.