Pursuant to section 33 of the Justice Act for North Rhine-Westphalia interpreters may be generally sworn [beeidigt], translators may be certified [ermächtigt], while language service providers (translators or interpreters) from other EU or EEA member states may be temporarily registered with the Court pursuant to section 43 of that Act.
Details regarding the requirements for being sworn, certified and registered by the court can be found on the website:
The required forms for applications etc. can also be found there.