Recall that a mapping routine can be referenced by an Assign node or by the input terminal or an output terminal of most types of Invoke nodes (see Artifacts from which mapping routines can be referenced) and that a reference to a mapping routine contains: (1) the name of the mapping routine; and (2) the name of the mapping file in which the mapping routine is located (see How mapping routines are accessed.)
To delete a mapping file:
In the EST Project Explorer, right-click the mapping file that you want to delete.
Select Delete.
The mapping file is deleted.