Object.UserValues[name].Remove()
The UserValue object has one method: Remove. The Remove (Method) behaves accordingly:
Removes the named property for the object from the document and decrements the collection’s Count property by one.
Scripts that reference the user-defined values fails unless the value is identified within a try-catch block. If the value is not identified within a try-catch block, the error message “Script Execution Error “%” (where % represent items not found) is written to the Console window.
If the named item value has its ReadOnly property set to true, the error message “Script Execution Error “%” (where % represents items that cannot be removed) is written to the Console window.