DOIs are persistent identifiers (PIDs), which means that they are intended to be a permanent means of identifying and accessing a particular resource. You cannot delete or change DOIs once they have been registered in the handle system (in "registered" or "findable" state). In general, it is better to avoid creating a situation in which a DOI is removed, if at all possible. Adjusting your workflow to make better use of Draft DOIs could help with such problems. Follow these steps to deactivate an erroneous DOI:
Change the state of the erroneous DOI to "registered" which will mean the DOI is no longer indexed in DataCite search and will not be found unless someone knows the exact DOI string. You can read more about DOI states here: https://support.datacite.org/docs/doi-states.
Update the URL of the erroneous DOI to a tombstone page. This can be your organizations own tombstone page or a generic one. You can read more about tombstone pages here: https://support.datacite.org/docs/tombstone-pages.
Updated about a year ago