If your shutter curtains are still good (almost certainly they're not), apply a small amount of oil to any moving parts. Use a wooden toothpick or something similar to apply the oil, otherwise you will use too much. If your shutter curtains need to replaced, lubricate the shutter mechanism later to keep your hands cleaner.

To remove the shutter curtains, remove the two brackets which are over the four drums. The drums near the cocking wheel with their gears are removed easily now. To remove the two spring loaded drums, pull the tension holding spring out of the slits on top of the drums. The tension will be released instantly.

I counted the original (?) tensioning turns by releasing the tension slowly with a screwdriver and counted 20 whole (40 half) turns in the non-cocked state. However, I found the repaired and lubed shutter to operate reliably and more smoothly with only 4 whole (8 half) turns.

To get the now relaxed drums out of the shutter unit, pull the top of the inner part (the one with the slit) up and lift the bottom out of the unit.