tb69
I think your response would be to tell the judge that your ex made the decision to retire and live on less income while knowing that he had three years of spousal support remaining. If you have knowledge of retirement income that he will have, such as 401K plans, or IRA's, retirement income from his employer, Social Security Income, then take those facts with you. If you do not have this information, you need to ask the court to make him disclose this information.
You will want this information in court with you; and, you will not want to waste the time of the court by going to court first and asking the judge to make him disclose this information. Therefore, you need to subpoena this information from him prior to the court date.
I recommend hiring an attorney to represent you and requesting that your costs be paid by your ex, who voluntarily created this situation.
If your ex is represented by counsel, I strongly recommend that you are, too.
If he is pro se, then perhaps you can hire a paralegal to assist you in preparing the proper paperwork, including the subpoena.
Good luck and best wishes.