The best summary of the paragraph is that a prince has three tactics to control a state used to freedom: destroying it, residing there, or forming a supportive oligarchy, with the latter being the simplest strategy.
The statement that best summarizes the central idea of the paragraph from chapter 5 of The Prince by Machiavelli is: There are three ways for a prince to hold a newly acquired state that is accustomed to freedom: ruin it, live there, or create an oligarchy that is loyal to him and the third way is easiest.
This concise statement reflects Machiavelli's analysis of governing acquired territories with a focus on those accustomed to freedom and self-governance.
By suggesting the establishment of an oligarchy friendly to the prince, Machiavelli outlines a strategic approach to maintain control with minimal resistance.