If you are developing your own S8, you will need to remove it from the cart in COMPLEATE darkness. Find a light tight area where there will be enough room to move and wait 5 minutes for your eyes to adjust. If you can see, MAKE IT DARKER!
The exposed film will display the words "exposed" on the film in the cart window, slide something underneath it (in the light) and pull it out slightly. Lights out.
Turn the spindle anti-clockwise until it clicks. This will disengage the ratchet-style thing-a-ma-jig inside.
This is the little arm near the central cone. (yours needn't be opened).
Now you can pull the film out of the cartridge. To prevent scratching the film, pull downwards through the slot. Depending on the size of your tank, you may with to cut the film at 7.5 metres. You won't need any more chemicals as E6 can be used more than once.
When the film is all in the tanks and all is light-tight, you may turn the lights on.
Inside the cart...