Would you like to know more about sales tax and registering a vehicle in New York at a DMV?
yes, paying the tax
When you register a vehicle in New York at a DMV office, you must either pay the sales tax or prove that sales tax was paid
is anything different for someone in the Army?
If you do not live in New York you can defer your sales tax payment.  You will need to complete the Sales Tax Exemption {Sales Tax Form}
Do you  know how to Register an out-of-state vehicle?
Bring your completed registration application and additional documents to a local DMV office.
in the case of a vehicle from a private owner?
provides
The out-of-state title is held by my lienholder. How do I register in New York?
certification from the lienholder that title certificate is a copy of the original certificate -  the copy of the title certificate and the certification of the lienholder must be on the same piece of paper
and To remove the lien?