Option 1:

ARTIFACTORY: How to remove a cold storage binding when the cold storage instance is no longer available

AuthorFullName__c: Erez Vadmani
articleNumber: 000005661
ft:sourceType: Salesforce
FirstPublishedDate: 2023-03-31T13:01:01Z
lastModifiedDate: 2023-03-31
VersionNumber: 2

If you still have access to the cold instance, and you can still start it over, then:

Start the cold instance
Remove the pairing via the UI