First of all, listen and take to heart what your editor tells you. They bring experience and an objective view to your manuscript, and they have a strong sense of what the publisher’s readership wants.
Next, if you feel strongly opposed about a particular suggested correction, discuss it with your editor. If you have clearly stated your rationale as to why you feel you should not make the changes and your editor still insists it’s the best way to go, I strongly recommend you yield.
And lastly, always keep in mind that even though your publisher has ownership of your manuscript, your name is on the front of the book and you shoulder the ultimate responsibility for the end product.