Hi, @Algkindom
Thank you for posting in Microsoft Q&A forum.
DC's can just be updated like any other machine.
To avoid the unwanted reboot or servers, the best approach may be to use the download updates but let us choose whether to install them option.
Make sure you have a good working backup of your domain controller. In case of emergency, you can rollback completely and restore a server to its original state if necessary.
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