Second the tail - this is the main way I unwrap any of my terrestrial snakes like ball pythons. My Morelia and Reticulated Pythons though have strong and long tails that are quite difficult to unwrap. The only ones that ever present a problem though are the larger carpets when it comes time for them to go back in their enclosures . . . even then though, its about consistent force, and focusing on getting the tail unwrapped first if possible, then using that to get the rest of the snake off.
In an emergancy situation with a larger boid (Let's consider +10'), I have always read that breaking the tail is like an emergancy oh crap button. Taking the tail and breaking it by making a U and squeezing, causes the snake so much distress that it immediately releases the host and trys to retreat. This is not the best method for the snake, and should ONLY be used if you allowed a SFE (stupid feeding error) to occur. Never attempt to unwrap by grabbing the neck on smaller constrictors, including ball pythons!