Large file not getting deleted from hard disk (IS 4.6)

I am working with IS 4.6.

I have created a service that store large files in hard disk for processing.but large file is not getting deleted after execution of the service.

I have dropped the references from the pipeline. i.e RID (under EDIValues) and references object(of wm.edi.b2b.util:EDIConcat service).

how and from where should i delete the reference of the file so that it will be deleted by the EDI module.

any tips are welcome…
thanks in advance.