i think the window crank has a clip. A "u" shaped clip. roll down your windows half way down. The roller of the window crank mus be pointed upwards so the clip wil be at "u" position. Slide a piece of cloth in to it. Pulling the cloth downwards while shifting from one side to the other, the clip will just pop and down goes your window crank. This is not easy coz you cant see whats happenin inside, but the clip will surely pop of coz the cloth will be pushing the "U" clip downwards.. hope

that helps...