Identify the court that granted the default judgment. Look at the complaint or summons. At the top of the document, you will find the case's style, which is the name of the court and the case number.
Draft a motion to set aside the default judgment. Samples and templates of such motions can be found in law libraries; some state statutes might contain a motion to set aside judgment template or language.
Explain why the court should set aside the default judgment. Laws differ by state, but in general you can cite your attorney did not file an answer in a timely manner, you were incapacitated during that time by illness, there was a court-made clerical error stating the wrong date or new evidence has been discovered. Read your state statutes for all acceptable reasons.
File the motion with the court and mail a copy of the motion to the plaintiff. Once filed, the court will schedule a hearing on your motion. Attend the hearing and state the reason(s) the court should set aside the default judgment.