Subtypes for a feature class or table can also be modified or deleted using the Properties dialog box for the table or feature class. You can modify any aspect of a subtype including its description, its default values, and its domains. Modifying each aspect of a subtype is done the same way as creating a new subtype.

NOTE: An exclusive lock is required on a feature class or table to modify its subtypes, default values, and attribute domains. Learn more about exclusive locks and schema locking.

1. In the ArcCatalog tree, right-click the feature class or table for which you want to modify subtypes.
2. Click Properties.
3. Click the Subtypes tab.
4. Click the left tab next to the subtype you want to modify or delete.
5. Make your changes or press the Delete key.
6. Click Apply or OK to save the changes.