You file a motion to modify child support based the change in circumstance (her higher income.) Once your motion is pending, you ask her if she wants to renegotiate or have the judge decide.
Did you have a lawyer assist with the pendente lite process? If so, you should use them again, if not, you should consult with one.
REMEMBER, my answer to your question is general in nature, as I don't know all the facts and circumstances relating to the specific person(s) and situations involved. You should always consult with an attorney prior to making any legal decision. This response does not constitute legal advice or create an attorney/client relationship.
You have to file a separate motion requesting a reduction based on changed circumstances, i.e. the reasons you indicated here.
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In order to reduce how much you pay your spouse in support payments, you first need to file a motion to modify child support/ spousal support. After that, you can begin renegotiating your support payments with your spouse. The changes in circumstance do seem to validate a change in support payments. Depending on how much you want to negotiate, it may be worth your time to consult with either a previous attorney or new attorney depending on your satisfaction.