If you can remowe the intire filmback from the camera something is not right.
Originally Posted by jazzmechanic
You can however open the filmback at all times.
From memory: On the left side on the back there is a slit for the darkslide: behind it there is a small hole in which a pin in the slide fits. You will also see two markings, on mine its a white circle (up) and dot and a white square (down). The same markings is on the darkslide. The darkslide is because you may want to change films midroll: insert darkslide, remove back, install another back containing a different film, pull darkslide and.......
Your film should be ok.