Change data source for large number of column elements

Lets say we have a domain /DOM1 which contains subdomains and lots of elements. One of the data sources (of many) that are used by elements in this domain is 'ActivityB'. Lets say that that 'ActivityB' besides holding ActivityBase also holds a lot of other stuff, including database links to other servers and ordinary tables.

Now we have an administrator that has decided that we should move ActivityBase from 'ActivityB' to another server that holds only ActivityBase, no db links, no other tables, no nothing. So how do we keep the IIM to be functional?

Changing the settings for 'ActivityB' so that it points correctly, to the new server will get all the elements that used to point to ActivityBase inside 'ActivityB' working. This will however point all other elements that used the db_links on the old 'ActivityB' incorrectly. I'd like to be able to change the data source for all the elements without having to edit the xml.