My ex and I divorced in 1997. At that time I was in the military and my home of record was NY (where she moved to at that time). I retired from the military in 2004, have a home in NV and claim it as my residence now ( although I am now married to a military member and currently live in DE). My ex has custody of the children and they all live in VA. Can I change the child support to the state of NV or VA now that I am retired? If so, how do I start the process?

You might be able to justify and have it changed to Va so long as she has residence there (usually 6 months) along with the children. She may try to argue that it is a reduction in child support en total because NY is very liberal when it comes to child support and goes beyond 18 in many cases. Are your children adults or still minors?