Hi Vivian, in response to your questions:

1. You will need to travel to your nearest Estonian Embassy to apply for the DNV.

2. Renewal of a DNV is not possible but you can apply again for a new DNV. Please be aware though that in Estonia (and the EU), the maximum period of stay of a foreigner on long-stay visas shall not be longer than 548 days within 730 consecutive days. Therefore, if you apply for a DNV for the maximum period of 1 year, after that you can apply for a second DNV for a maximum period of six months. These would be two separate applications and decisions and, if you are successful in both, two separate stay visas. After staying in Estonia for 1,5 years you will be required to leave Estonia. Please note that staying in Estonia on a DNV has no advantage with regards to gaining any form of residence permit in Estonia.