I am not sure I understand your question. If there is a current child support order in place, you must seek to modify that order through the court that retained jurisdiction over your case. This usually requires a significant and continuing change in circumstances.
If you are seeking to have your child support changed, I would consult with an attorney to best deal with your situation.
Nothing in this communication should be considered legal advice. Nor should this communication lead you to believe that an attorney-client relationship has been created. Only after thorough analysis of your case with you in my office can I provide effective legal advice on your specific issue.