Question on Switching Cultures/Rulers for a Province

[Jestor]

When I get CK, one of the first AAR possibilities I'm considering doing is taking one of my rp characters and putting him in as the Catholic Castilian Count of Valencia.

How would I change Valenica from its current Muslim state and change the ruler to the custom created Carlos Patriarch?

 

[unmerged(21482)]

Change Valencia ruler's religion from muslim to Catholic in character file.