Prerequisites
Note that you can only delete a type (data element, structure, table type) in the ABAP Dictionary when it is no longer used in other objects (for example in tables, structures or programs).
Procedure
With you can get an overview of where the type is still in use. Make sure that the type is no longer being used in other objects.
A dialog box appears in which you are asked to confirm the deletion request.
Result
The type is deleted if it is no longer being used in other objects.