retraction BADI triggers automatically upon data write to BPC model, we cant' call directly.
(Its possible to call if you have any expertise in ABAP).
Check below link on how to pass the parameters for this test program - http://scn.sap.com/people/pravin.datar/blog/2009/08/28/automate-execution-of-any-data-manager-package
Let me know if you need any more info.