I've got an old Sure Shot 80 Tele that still has film in it, partially used. I'd like to have the film developed but I no longer have a battery for the camera and would prefer to not buy one, as I don't intend to use the Sure Shot again. As I have no instruction manual (and Canon's website was useless for support), can anyone please tell me how to manually rewind the film that's in the camera? Thank in advance, Megan