Conversation so far:
Did Isabella live in Granada?
At the end of the Reconquista, only Granada was left for Isabella and Ferdinand to conquer.
Who were they fighting against to conquer Granada?
The Emirate of Granada had been held by the Muslim Nasrid dynasty.
Were they able to conquer Granada?
On 2 January 1492 Isabella and Ferdinand entered Granada to receive the keys of the city, and the principal mosque was reconsecrated as a church.

Question: What did they do to reorganize the empire?
Self-contained rewrite: What did Isabella and Ferdinand do to reorganize the empire?