You will need to take the door panel off. If I remember correctly the door winder handle has a cross headed screw which you can access by removing the small plastic cover plate. Pull off the panel and you will need to cut or tear the alcathene layer to get at the mechanism. Push the bottom of the cradle while turning the winder ( put it back on temporarily ). This will g the window closed for you and you will be able to get another mechanism at a scrapyard. To replace this you will have to drill out the pop rivets. Good luck.
