Funny that you started two different threads, three minutes apart, asking the exact same thing. The reality is that you're not going to get different answers.
You'd be well advised to not even try to break the contract. If you fail to pay, the owner or rental broker can sue you for breach, and will be extremely likely to win both damages of your payment failure, plus court costs (which could actually exceed the money you owe on the rental.). And if you've already paid, that money is gone.
Don't do it. You almost certainly signed a contract that was non-refundable (the standard for all brokers insofar as I am aware.) There isn't wiggle room there. If you haven't yet paid a portion and just decide to not perform as per the contract, it could ultimately cost you a whole lot more, plus ruin your credit rating.
The issue is a good one to see raised for other prospective renters who might read this. Non-refundable payment up front means exactly what it sounds like it means. This is the central disadvantage/risk that one accepts when choosing to save a lot of money by renting DVC points, rather than booking on cash through Disney.