Dear Bcampbell,
Thank you for your query.
Can you achieve the desired changes manually through the user interface?
If so, it is probably possible programmatically as well.
The procedure for you to explore this yourself is always the same:
Set up a simple minimal starting point situation manually through the user interface.
Explore the elements and their properties using RevitLookup, BipChecker, the element lister, and other, more intimate database exploration tools:
http://thebuildingcoder.typepad.com/blog/2013/11/intimate-revit-database-exploration-with-the-python...
Make the desired modification.
Analyse what changed.
Now you know what to do to achieve the desired result.
I hope this helps.
Best regards,
Jeremy