Business Objects .Net SDK " Editing/Changing a Webi Data Source"

We are using Business Objects 3.1 with the .Net SDK coding in vb2005. I need to change the datasource for WebiDocuments but not just at run time, we would like to be able to change them when a datasource/Universe changes prior to running the reports. Which SDK should I use and is there any examples someone might have that they can share.