How to Delete a Oracle Weblogic Server (WLS) Domain

If you want to delete a WLS domain, all you need to do is remove the domain directory /user_projects/domains/ or .
There is no special tool or script required to delete a domain. A domain is nothing but a configuration in WebLogic Server, not an installation. So for deleting a domain, uninstall packages are not needed. All the information related to the domain will be maintained within the domain itself. So when you remove the domain root folder, all the details of the domain are completely cleaned up.

The entry for the domain which we are deleting should be removed from the domain-registry.xml file from $MIDDLEWARE_HOME

It is not required to change the Metadata Service (MDS).

Also you need edit the "nodemanager.domains" file under WL_HOME/common/nodemanager to remove domain information from that file.
The nodemanager.domains file specifies the domains that a Node Manager instance controls, and should contain an entry specifying the domain directory for each domain the Node Manager instance controls, in this form:

domain-name=domain-directory

Take a backup of the "nodemanager.domains" file before editing it.

When creating a domain through the Configuration Wizard, the domain name should be automatically added to the nodemanager.domains file. If in any scenario we need to add it manually, we should add the line "domain-name=domain-directory" to the same (nodemanager.domains) file.