My ex wife and I want to agree difference to the consent order. How do we do this?

[ap35]

We have a consent order which states that I have to pay rent whilst we live jointly and maintenance of the same amount whilst living separately. However, due to the way it was written, my ex wife has to move first. She wants me to move first. We agree that I should be paying one or the other, but that's not what the order says. Do we need to get the order changed? And how do we do that? or can we have a separate agreement between ourselves which super seeds the court order. We have spent too much on lawyers already so want to avoid further costs.