It took over 18 months from my first contact with the office of the Virginia Tax Commissioner to receipt of the final letter acknowledging that I was no longer a domiciliary resident of Virginia.
We had already taken MANY steps to break ties - owned no property or cars, were removed from the voter registration rolls, had no driver's license (actually, once you no longer live in Virginia you can't have one, and you are required by VA law to report any change of address within 30 days), changed to a foreign address on ALL financial accounts, and on and on. Bear in mind that DH is a Brit, and I had only lived in VA for 11 years, and was in my mid-60s when we began the process.
It was still onerous - copies of everything imaginable that related to our life in the UK, a form that asked many questions, proof of this, proof of that. Thankfully we had no children in VA or any other relatives there - any 'blood ties' can be used against you. I also researched multiple rulings from the office of the Tax Commissioner, to determine why someone succeeded, and why the change of domicile was refused.
It is not fun, not straightforward, and not easy, but it can be done. .Just don't assume that because you no longer live there, you're out of their control.