Sorry, found that while I was looking and I had to share it.
From what I've heard, you hold the button for 10 seconds until it blinks and then pushing and holding will increase the threshold in increments of 5fps and then pushing and holding again will reverse it, and so on, then I'm assuming that you just press it again to confirm the settings or leave it idle for a bit. I've also heard that only some of them are capable of being programmed.
Do I have any first hand experience with reprogramming? No, I don't. But, I can still regurgitate what I've heard.