ARIBA to SAP issue in message mapping

Hi,

I have a scenario from ARIBA(WSDL) to SAP(RFC) using PI as a middle ware.

The mapping we are using is standard,but in SAP they have changed the standard RFC(BAPI_CREATE) to customized RFC(BAPI_CREATE_001).

But when i am trying to change the RFC in the message mapping(i.e BAPI_CREATE to BAPI_CREATE_001) could not able to do the change.Could you please let us know how to change the RFC from BAPI_CREATE to BAPI_CREATE_001.In mapping the edit icon has been disabled.

P.S: When we imported the WSDL file,the mapping has been came automitically. Is there any tool to do mapping between ARIBA to SAP?