This is not a recommended repair procedure. For a jammed shutter that will still work under the following circumstances.
If . . .
1. If the shutter will fire with a cable,
2. If the shutter will not fire with the button,
3. If the film crank will not advance on its own and
4. If the film crank will advance while depressing the shutter button
then smack the crank end of the camera on a carpeted floor a few times. I mean if it's a boat anchor anyway, might as well take a crack at it. This freed up the shutter button mechanism and allows the camera shutter to fire by using the button, not just the cable release.