there is a best core dissasembly tool that pushes the tops off the pin stacks, the best core is put into the tool and 6 rods enter the holes on the bottom of the core, (these holes are of a smaller diameter than the pins themselves for applications were the core may be turned 180 degrees to prevent the master key wafers from fallin into them) the rods push the pin stacks against the springs crushing them, and all of this pushes out the pin stack cap. to reassemble, usualy new springs and new pin stack caps are used. You can also drive out a column with a sixteenth inch pin punch available at the hardware store. this will drive out one collumn when hammered in. perhaps you can reuse the pinstack cap, if you do you might want to crimp the top of the cylinder where the colllum comes out by dinging it with a centerpoint punch or other such tool. Or you could place a round ended tool on the top of the pin stack and hit it once, causing the cylinder to spall into the collumn drilling and tighten the pin stack cap. So called grinding of mushroom pins is a bad idea, look for mushroom pins made on a machine and of the same diameter as the best pins. If you had a plan on how to hold and turn the little driver pins while grinding it, I would be very interested in learning how that would be done.
