BAPI / RFC to web service

Hi

I am trying to expose a BAPI/RFC as a web service using web application server 6.3.

I have looked at all the available documentation, I think, but there is no mention of a direct step by step procedure to do this.

Can some one help me? If you look at many presentations for web applicatio server 6.3, they all say that it allows exposing BAPIs/RFCs/RFMs/IDOCs as web services. But I cannot find how.

Thanks in advance.