The person who pays child support or the person who gets those payments for the child can ask the court to change the amount paid. Either side can ask for a Modification of Child Support. The person who wants the court to change the amount of child support must file a Rule to Modify Child Support.
This guide has a sample blank form to ask the court to change child support. There is also a form that uses a computer to fill in the information needed. See the information in this guide about using the computer program to create a form to ask the court to modify (change) child support.
You will need to complete your online form and file it with the court. If you can't afford to pay court costs in advance, you will also need to file at the same time court papers to ask the court to allow you to go forward with your case without paying court costs up front. These papers are called a motion or application to file "In Forma Pauperis." There is a computer form to fill out the In Forma Pauperis papers. Go here to get the In Forma Pauperis form online on the site of the Supreme Court of Louisiana.
You must also arrange for court papers to be "served" on the party on the other side of the case, as well as on any state agency, if it is involved in your case. There will likely be a court hearing so the judge can listen to what each side has to say before making a decision.