door lock actuators.....
great idea and i believe its pretty easy, the inner door just pulls off. it is held on by plugs that snap in. then theres a plastic sheet held on by some kind of sticky black sealant. just peel that out of the way, then you should be able to access it pretty easily. mine is broken too, it was making a machine gun noise when i would lock or unlock the doors. so i just went in there and unplugged the actuator so it only works manually now. i think it should be pretty easy to do it yourself, save that money for something else.