Hi, and thank you for your interest!
Vivaldi is being translated using Weblate, a web tool designed to ease translating for both developers and translators.
Translation project for Vivaldi into Norwegian Nynorsk currently contains 3700 strings for translation and is 71.5% complete.
If you would like to contribute to translation of Vivaldi, you need to register on this server.
This translation is open only to limited group of translators, if you want to contribute please get in touch with project maintainers.
Once you have activated your account just proceed to the translation section.