I am assuming you are asking, how do you ripple through parts libraries, changing one schematic symbol for another. The route to do this, assuming your mapping in each selected part will not be adversely affected by the action, is to run a report on where that symbol is used from library manager, then use its result to create a PGF script using the Library Toolkit for import in the library manager. Refer to http://pulsonix.com/learning.asp for details on the Library Toolkit. Just be careful that the symbol swap does not cause mapping problems!