[Hugh]

Curt,

Drop a little WD40 or Liquid Wrench on the threads from inside and let them soak for a few hours. Place a screwdriver that fits the slots into the slots and tap the top if the screwdriver handle a few times to help loosen the threads, then try to unscrew using downward pressure on the screwdriver to keep the blade from jumping out of the slot. It is imperitive that you use a screwdriver with parallel sides to the blade (a gunsmith screwdriver) and not the common household type with the tapered blade.