Like Rob says, you can release the buttresses manually. Use a very small screwdriver or a something like a 2mm allen wrench. Stick it vertically in the hole right behind the buttress pin (toward the rear of the car) and force it forward beside the pin on the inner side ( toward the center of the car). The pin will pop right up.
A little cursing may help also, it can be a tricky maneuver the first time you try it.