Sounds like a hot dip in antifreeze and a crock pot are needed. I do this when I change bearings. It also does a decent job cleaning and softening up gunk. In looking at the exploded diagram of a .40nx, the manual shows a cylinder liner. If it wont budge with the engine cold, you need to heat the engine and use some wood or plastic to pry it loose through the back plate opening. Prying from the top is risky. Dont use a screw driver unless its protected by something to keep from gouging the liner. With the liner out, you should have room to move the conrod off the crank pin. Depending on how the piston is made will determine if you can slide the conrod off the pin when in the liner.
Edwin