"The screw in the pointer dial is RH threads. The slotted nut under that has LH threads. I took a large straight blade screwdriver and angle ground the outer edges and notched the center. Wind the shutter first, then try to get it loose. Then fire the shutter and finish unscrewing it. Good luck and make sure you check the shutter curtains for pin holes." quoted from Upnorthw in another post on FX2