What's the fastest way to unregister an NI product to put up for sale?

[rdej47]

Hey guys I sold my Kore 2 last week and got rid of my serial number in the service center but I guess that wasn't enough to unregister the number. What is the quickest way to unregister that number through NI. I really don't want to call them, their phone support is balls. Is an email simple enough?

[Lecko]

I emailed them with all the details and it took a couple of days response, but they removed everything from my name, easy